Modern Christian Landscape in Nanjing , China : A Literature Review

Between the First Opium War in 1840 and the founding of the People’s Republic of China in 1949, the development of modern Christianity in Nanjing expanded beyond the parameters of faith and spirituality, while interacting closely with Nanjing’s city life and space across a wider spectrum, such that a unique religious and cultural landscape was produced. Through an extensive literature review of 115 articles identified on this topic, this paper analyzes the development of the space of Christian churches in Nanjing, and further documents the pattern of interactions between Nanjing’s development as a modern city and its religious cultural landscape. Moreover, drawing from the theoretical perspective of Sense of Place, the paper summarizes the characteristics of religious cultural landscape in the aspects of vision and structure, function and modernization, and memory and identity, and points out that the Christian landscape should also be conducted from the activation of material form, local functions and historical meanings to achieve sustainable development of Christian landscape. Finally, the paper offers planning and design strategies for the continued growth of Christian landscape in Nanjing.


Introduction
From ancient times to the present day, there have been many religions and religious cultures in Nanjing, the capital of Jiangsu Province, and one of the most rapid economic developing regions in China (Figure 1).In the long course of history, the religious space is not only the material carrier of city's belief activities but also the direct reflection of urban landscape features [1].In ancient times, southern China was the earliest location where Buddhist culture propagated [2].In the Ming Dynasty and Qing Dynasty, Catholicism and Christianity were introduced to China from the coastal cities in southeast China.Then, these religious traditions and beliefs spread to other cities, making their way inland to cities such as Nanjing.Many cities that the missionaries chose were very important cities at that time.
Nanjing is pivotal to the introduction, growth, and development of Christianity in China, suffering from the "Nanjing religion cases (1616)" that caused the banning of Christianity spread [3] to the developmental climax during the Qing Dynasty and the Republic China from 1912, after Nanjing was established as the capital, and subsequently became the center of social changes in China.Thus, Christianity influenced and interacted with the city's development process.Especially from that time to 1949, religious cultures interacted immensely with Nanjing's city life and space, producing unique religious cultural landscapes.
The cultural landscapes represent the diversity of human activities that accompany the natural landscapes.It is the composite of natural and human elements at any given time.Religion is an important part of culture, and its vestiges imparted on the cultural landscape are very obvious.Sauer C.O. and the Berkeley School of Thought consider religion as super organic construct, which influences cultural landscape [4].Today, with the accelerating pace of urban development and the increasing complexity of urban space and functions, religious cultural landscapes are under threat.In urban planning, a critical question Nanjing faces is whether the complexity of the religion means the religious cultural landscapes should be isolated from the rapidly changing urban environment, or passively accept stylistic protection and excessive tourism exploitation, with neither being appropriate [5].
important part of culture, and its vestiges imparted on the cultural landscape are very obvious.Sauer C.O. and the Berkeley School of Thought consider religion as super organic construct, which influences cultural landscape [4].Today, with the accelerating pace of urban development and the increasing complexity of urban space and functions, religious cultural landscapes are under threat.In urban planning, a critical question Nanjing faces is whether the complexity of the religion means the religious cultural landscapes should be isolated from the rapidly changing urban environment, or passively accept stylistic protection and excessive tourism exploitation, with neither being appropriate [5].Christian cultural landscape is a special kind of cultural landscape.China began to protect historical heritages in 1949 and focused on individual relics at the beginning.In 1982, the government issued the "Law of the People's Republic of China on the Protection of Cultural Relics" (the Law) and Christian cultural landscape is a special kind of cultural landscape.China began to protect historical heritages in 1949 and focused on individual relics at the beginning.In 1982, the government issued the "Law of the People's Republic of China on the Protection of Cultural Relics" (the Law) and expanded the scope to include historical sites and historical cities.Since the 21st Century, marvelous achievements have been made in the protection of cultural relics.The Law has undergone five rounds of revisions.Some cultural relics and intangible cultural heritages are listed in the catalogue of the World Heritage and the catalogue of Masterpieces of the Oral and Intangible Heritage of Humanity.
However, the protection of cultural landscape heritage faces challenges due to rapid urbanization.These challenges are ubiquitous in China and reflect the dilemma of heritage protection in general-striking a balance between economic development and protecting the true value of cultural landscape.
The current "protection-style" practice tends to remove the religious space and cultural landscapes from the collective memory of the city and its core values, instead transforming these spaces and landscapes into "postcard" historical and cultural blocks and billboards for the tourism industry.This excessively secularizing and homogenizing model of "protection" has led the religious landscapes in Nanjing to lose their identities and features, such as building styles, spatial scales, relationship with the urban context, and the cultural system.These religious spaces and cultural landscapes become similar to their counterparts in many other cities in China [6].In short, the current model of protection does not respect the history, value, and significance of cultural landscapes creating areas that lack a proper philosophical foundation, like "water without a source and a tree without roots" (Yangming Wang 1472-1529).
The strategy of sustainable development of cultural landscape is an important research topic in the field of cultural landscape protection.It is difficult to make its historical significance understood by younger generations and therefore to sustain these cultural landscape features and sites.Only conserving the physical landscapes is not enough to make their comprehensive value recognized by the general public, as their core value plays a significant role in the continuation of local memory.
To preserve Nanjing's Christian cultural landscape heritage based on sustainable objectives, and to change the mode of cultural landmark preservation to derive commercial benefits, it is necessary to clarify the value of Nanjing's Christian cultural landscape heritage with regard to the establishment of the area and the establishment of collective memory.As such, it is necessary to study the following topics: (1) the development and evolution process of Nanjing's Christian cultural landscape heritage; (2) the states and types of Nanjing's Christian cultural landscape heritage; and (3) the interactive relationship between the spatial distribution characteristics of Nanjing's Christian cultural landscape heritage and urban development.Subsequently, the establishment of a historical framework related to the development of Nanjing's Christian cultural landscape and the determination of the core value and characteristics of Nanjing's Christian cultural landscape heritage from an analytical historical perspective provides a new orientation and basis for future preservation efforts.
The above-described research encompasses history, geography, and landscape studies content.During the literature review, it is found that existing academic studies regarding Christian cultural landscape heritage are relatively small in number, and are distributed across different academic disciplines.Each academic discipline approaches this type of research from its own perspective.For example, geography studies emphasize research on the spatial distribution of Christian cultural landscape heritage, while history studies emphasize research on the processes of the spread of religion and the development of religious landscapes.However, there is a severe lack of research based on urban backgrounds that addresses consolidated preservation efforts.As such, it is necessary to utilize a systematic literature review method to consolidate research dispersed over various academic fields in order to establish an innovative system of preservation methods based on sustainable research objectives.These objectives include: the preservation and restoration of physical representations of religious and cultural heritage sites, reestablishment of the historical roles of these sites in daily life, and allowing residents to reidentify their historical significance and thus eventually gain a sense of identity collectively among residents.Until these objectives are met, sustainable values capable of transferring Nanjing's religious cultural heritage between generations cannot be formed.

Materials and Methods
We adopt a systematic literature review method with the objective of forming a stand-alone format of literature review in order to conduct a descriptive and extensible comprehensive analysis of literature.The descriptive method was used to study the development and evolution process of Nanjing's Christian cultural landscape heritage.The extensible literature review method and map analysis method were used to summarize the core value and characteristics of Nanjing's Christian cultural landscape and further proposed a sustainable heritage revitalization strategy.
Subsequently, this study establishes a descriptive framework of the development and preservation of Nanjing's Christian cultural landscape heritage.The key research steps of this paper include research process planning, literature retrieval, literature analysis, and the formation of descriptive and extensible research conclusions.Finally, based on the above works, this paper provides a valuable methodological framework for future preservation of religious cultural landscape heritage.
We first determined databases for literature retrieval.As the subject of this paper is the Chinese city of Nanjing, in order to obtain relatively complete localized as well as internationalized research results, we have chosen to use the CNKI (China National Knowledge Infrastructure), Web of Science ScienceDirect, Taylor & Francis, Wiley, SpringerLink, and MDPI to search peer-reviewed journal articles and conference proceedings.We defined our data retrieval period as 1996-2016 because research results from this period are mostly concentrated on the research topic area.
We then used keywords to search, including Christian cultural landscape, Nanjing Christian cultural landscape, and Nanjing Christianity.For instance, when searching CNKI database, we first used "Christian cultural landscape" as the keyword for literature retrieval.This step produced six relevant papers, of which one paper was unrelated to Christianity, and was deleted.The remaining five articles come from four different countries: Africa (2), Spain (1), Greece (1), and China (1).It is evident that, although Christianity entered China in the year of 635 and has developed for more than 1300 years, the material cultural heritage left by Christianity in China over the long course of history has received little attention from academia.However, the importance of this heritage as a unique form of cultural landscape cannot be emphasized enough.
We then broadened the search to encompass the current focus related to Christianity in Nanjing.We used the keyword "Nanjing Christianity" to search, from which we retrieved 356 articles.Among these, 86% were studies based on social science fields, and were distributed across the fields of religion, modern Chinese history, biography, public administration, higher education, and literature.Furthermore, the studies based in the field of social sciences are related to a broad variety of content, primarily including Christianity, Nanjing's nationalist government, missionaries, religious proselytization, and the Nanjing Massacre.
Our search of the Chinese language database CNKI shows that research related to Christianity in Nanjing has a long history and covers a broad variety of content.However, material landscape heritage has long been neglected by academia.Despite the fact that China began to conduct landscape heritage preservation activities in 1949 and has enacted many relevant laws and regulations, there remains a relative lack of research and practice with regard to Christian heritage.
We continued to search Web of Science database using the aforementioned three keywords.When using "Christian cultural landscape", "Nanjing Christian cultural landscape" as keywords to search, no literature was identified.Then, we used "Christian landscape" as the keyword to search we retrieved 92 articles instead.After analyzing the content of these studies, we removed the articles that in the areas of Business Economics, Government Law, Physical Geography, Anthropology, Sociology, Environmental Science Ecology, Education and other articles that has little relation with our study, which resulted in 57 research articles.There were 35 articles related to the study of Christian landscape.
We repeated these steps to search ScienceDirect, Taylor & Francis, Wiley, SpringerLink, and MDPI, from which pool we further screened them based on their relevance to the research questions after reviewing titles and abstracts.We finally chose 115 articles to review the full text.In this pool of articles, the Chinese language literature mainly conducts systematic discussions of the relationship between the historical development of Christianity and major historical events.With regard to the field of material landscape, English literature tends to focus on research related to the formation of religious landscapes, Christian landscape tourism, the preservation of religious architectural landscape symbols, religious landscapes, and the establishment of local identities.
Based on the analysis of these studies, we found that there is a lack of judgment on the core characteristics and value of the Christian landscape of Nanjing.Furthermore, among social sciences research and material landscape research, there is also a lack of investigation that echoes urban development, and a lack of research that shifts from history.As such, we utilized a systematic approach that combined methods to highlight the core characteristics and value of Nanjing's Christian landscape.We subsequently used map analysis methods to supplement fractured relationships between history and space, and between culture and location.This helps to guide the formation of a preservation system based on the objectives of sustainable local construction.The results are presented below.

Overview of Modern Christianity Development in Nanjing
Christianity was introduced into Nanjing in 1867 by foreign missionaries after the Second Opium War (1856-1860).However, it was not until 1873 that the American missionaries rented a house and founded the first church in Nanjing [7].By the end of the Qing Dynasty, the growth of Christianity was accompanied by Western imperialist's military aggression towards China.However, church-run schools and hospitals also brought Western science, medicine, technology, and culture into Chinese cities that were undergoing transformation [8].During the Republic of China, the development of Christianity was quite rapid in Nanjing, with a steady growth in the number of Christians [7].As a result, the number of churches increased substantially in Nanjing during this period.In the Chinese People's War of Resistance Against Japanese Aggression (1931)(1932)(1933)(1934)(1935)(1936)(1937)(1938)(1939)(1940)(1941)(1942)(1943)(1944)(1945), some foreign missionaries migrated to other cities in China (e.g., Chongqing and Chengdu).Other missionaries remained in Nanjing and formed the International Committee, which later established the Nanjing Safety Zone in order to provide shelters and assistance to a large number of refugees during the War [9].Thus, this group of missionaries witnessed a historical moment in Nanjing, together with the residents.After China's victory in Chinese People's War of Resistance Against Japanese Aggression, many foreign missionaries scattered.Some moved to Taiwan and others returned to their home countries when the Republic of China's government retreated to Taiwan.Only a small portion of missionaries stayed in Nanjing to continue their missionary works.After the founding of the People's Republic of China in 1949, the Nanjing Municipal Government extensively promoted religious freedom, which enabled Christians to resume their regular religious practices (Table 1).It is evident that the development of Christianity in Nanjing was a "mirror" of the ebbs and flows of the city's history, as Nanjing was the focal point of upheavals in China's modern history [8].Religious cultural landscapes can be classified into material landscapes and no-material landscapes [10].The former includes religious architecture and sites, religious paintings, and religious statues.The latter includes religious rituals, religious music, and religious thoughts [11].Churches are representatives of material religious landscapes, embodying the spatial form of the Christian culture.The spatial distribution and evolution process of Christian churches is the spatial expression of the religious landscape's development [12].In fact, the spatial distribution and evolution process is also the territorialization of Christianity during its process of adapting to Chinese society.
Nanjing is located on the downstream portion of the Yangtze River.It is an ancient capital with more than two thousand years of recorded history.There are many rivers, lakes, and mountains in the city, and Nanjing serves as a typical example of the achieving a harmonious relationship between man and nature (the city of mountains and water).Nanjing experienced two early construction booms-one during the Six Dynasties period (AD 222-589) and the other during the Ming and Qing dynasties (AD 1840-1368)-which formed a classic and successful ancient urban pattern that included irregular walls built to follow the course of the water and functional districts that were suited to the needs of the ancient city.The most important functional districts of ancient Nanjing included the palace district in the east side of the city and the bustling commercial district centered on the Nanjing Confucius Temple along the banks of the Qinhuai River within the area fenced in by the city walls [13].These classic urban patterns have had a lasting impact on the spatial distribution of the boundaries of the Christian spatial landscape in Nanjing-with both spatial clustering and spatial expansion having lasting effects.
However, the classical urban layout and the large bustling streets that formed within the Ming Dynasty city walls of Nanjing during this prosperous period of urban development were severely damaged during the Taiping Heavenly Kingdom Movement (1851-1864).During this period (1851-1864), a majority of the city areas (excluding the urban core) were changed to wildness, according to records from a visiting diplomatic mission that included English naval captain Edmund G. Fishbourne, French priest Stanislas Clavelin, and American pastor Michael S. Culbertson.In Discussions of Establishing the Heavenly Capital in Nanjing, Renkui Hu describes the "wide streets and pastoral beauty" of the city and discusses the dramatic differences between urban and agricultural areas.The first church in Nanjing was built after the Taiping Rebellion.These sudden changes of city space and appearance also largely determine the clustering characteristics of the early Christian landscape [14].
The ancient urban pattern of the city was altered after Nanjing was established by the Nationalist Government as China's capital city in 1927.Nanjing's Nationalist Government began modern urban construction in 1929, according to the City Plan of Nanking.Between 1929 and 1937, Nanjing constructed modern roads and new urban functional areas that disrupted the ancient city patterns.During this same period, Christian churches and their landscape experienced a period of rapid growth accompanying urban modernization.As a result, the Nanjing urban area expanded and so did the spatial distribution of Christianity.
Religious cultural landscape and urban development influenced each other in a sophisticated manner.Study of these mutual influences facilitates the understanding of their complex interrelationships and interactions.

Centripetal Development (1860-1912)
Based on the unfair Sino-foreign treaties that followed the First Opium War (1840-1842), the Western imperialists gained privileges from the "five treaty ports", and foreign missionaries were allowed to build churches in China [15].Subsequently, many European and American Christian denominations sent missionaries to China.In 1874, American missionaries Wei Li and Li Man rented an open space located on "the Four Poles" (now Mochou Road), and built a new modern Christian church in Nanjing (1884) [7].From 1860 to 1912, eight new churches and four additional congregation assembly points were established in Nanjing (Table 2).These buildings were mainly located in the densely populated urban area south of the city (Figure 2).According to the German Löbbecke, who lived in Nanjing at that time, by the end of the 19th century, there were approximately 800,000 residents in Nanjing.These residents, however, only occupied one-tenth of the city area, which was the densely populated and commercially prosperous Confucius Temple area [16].
Sustainability 2017, 9, 2155 7 of 25 lived in Nanjing at that time, by the end of the 19th century, there were approximately 800,000 residents in Nanjing.These residents, however, only occupied one-tenth of the city area, which was the densely populated and commercially prosperous Confucius Temple area [16].  2 for more information on each church.Church numbers are in accord with that in Table 2.  2 for more information on each church.Church numbers are in accord with that in Table 2.
These 12 churches and congregation assembly points mainly distributed in the south of the city and circled around the Drum Tower.The spatial distribution of these early religious buildings evidently formed a centripetal development pattern with the old city center being the core area.Among the 12 churches and congregation assembly points, only three of these churches have been rebuilt and remain at the same places till now, including the Four Poles Church on Mochou Road (established in 1884 and rebuilt as Hanzhong Church in 1936), the Drum Tower Church located in the Drum Tower Park (established in 1886), and the St. Paul's Church on Taiping Road (established in 1910 and rebuilt in 1922) (Table 2).

Agglomeration and Leapfrog Expansion (1912-1937)
After the establishment of the Republic of China, and with support from the local government, the development of Christianity reached a temporary peak.In the Provisional Constitution, Dr. Sun Yat-sen clearly stipulated that people have the freedom of religious belief.In 1927, Nanjing was reestablished as the capital of the Republic of China, and Chiang Kai-shek became the military and political leader.Later, Chiang adopted a policy to protect and set a preference for Christianity in religious beliefs.These actions greatly promoted the development of Christianity in Nanjing [17].In 1937, prior to the Chinese People's War of Resistance Against Japanese Aggression, there were more than 10,000 Christians in Nanjing, with dozens of churches and congregation assembly points constructed and in use.In particular, eleven new churches were built in the old city area (Table 3 and Figure 3); eight new churches were founded in Jiangning Lishui District; seven were newly established in Liuhe District; five were built in the Pukou District; and two were founded in the Qixia District.
The spatial distribution of the churches in this era still showed a centripetal development pattern.However, the central, clustered area evidently displayed an agglomeration of land uses that were expanding.In addition, this expansion gradually moved out of the southern boundary of the old city, breaking through the Ming Dynasty City Wall (see Figures 1a and 2) and dispersing into the surrounding towns, manifesting a leapfrog-style development pattern.This leapfrog-style pattern was also closely linked to Nanjing's spatial expansion [18].This era marked the flourishing period of Christianity in modern Nanjing until the outbreak of the Chinese People's War of Resistance Against Japanese Aggression in 1937.The spatial layout of Christian churches in this era demonstrated the following characteristics.3 for more information on each church.Church numbers are in accord with that in Table 3.  3 for more information on each church.Church numbers are in accord with that in Table 3.  [7].Note: See Figure 3 for specific locations of these churches.Church numbers (first column) are in accord with that in Figure 3.
In New Functional Areas at the City's Core Implementation of the City Plan of Nanking in 1929 led to obvious changes in the spatial pattern of the city [19].Nanjing started to exhibit modern urban planning styles.The Plan delineated six functional districts in the old city: central political district, central business district, residential district, cultural and educational district, municipal administrative district, and industrial district.These six functional districts provided political, economic, cultural, and other related modern city functions.These districts in total hosted 76.6% of the city's total population and substantially expanded the city's built environment.Parallel to the founding of the country's capital, Nanjing reestablished connections with Christianity.The Chinese Church pursued an "Anti-Communist, Pro-Chiang Kai-Shek" policy.At the time, President Chiang Kai-Shek and First Lady Soong Mei-Ling were both Christians, which greatly promoted Christianity among government officials.As a result, along with the construction of new administrative and residential areas for high-ranking government officials, Christian churches rapidly emerged and clustered in these areas, with characteristics that were distinctly different from their initial development period.
For example, The City Plan of Nanking changed the functions of Nanjing's Xinjiekou District and rapidly turned it into a new commerce center.At the same time, the establishment of the National Central University (old campuses of today's Nanjing University and Southeast University) and its affiliated colleges in the Drum Tower District continued to expand the urban functional areas toward north of the city.
The Christian denominations quickly founded two churches in the above-cited functional areas.For example, in 1936 (Figure 4), Christian churches were mainly concentrated in the first district (administrative), the second district (business), and the fifth district (cultural and educational).Some churches were distributed in the third and fourth districts (residential).There were only two churches built in the sixth district (industrial).With the development of urban functional areas, the churches moved outside of the traditional residential areas and reemerged in the administrative, business, and cultural and educational districts.

In Densely Populated Areas
In the beginning of this stage, Christianity still converted disciples primarily through preaching sermons [10].However, for a long time after the introduction of Christianity under unfair treaties, it aroused strong resistance among the people, especially the educated intellectuals [8].In contrast, people in lower-classes who did not have much education were as pure as driven snow.They were willing to adopt Christian faith [20].Therefore, the missionaries would target the lower-classes people as potential disciples, which led the missionaries to prefer building churches in densely populated, especially in old city residential areas.
The total population of Nanjing has been increasing generally since 1912.According to Nanjing Population statistics, the population was 269,000 in 1911, 497,526 in 1928, and then 795,955 in 1934 [21].
After 1927, with the implementation of the City Plan of Nanjing, the densely populated area expanded from the southern portion of the city to new functional districts.As shown in Figure 5, although the fourth district (residential) was still the densest area in terms of population, the second district (business) and the fifth district (cultural and educational) absorbed a large proportion of the population.

In Densely Populated Areas
In the beginning of this stage, Christianity still converted disciples primarily through preaching sermons [10].However, for a long time after the introduction of Christianity under unfair treaties, it aroused strong resistance among the people, especially the educated intellectuals [8].In contrast, people in lower-classes who did not have much education were as pure as driven snow.They were willing to adopt Christian faith [20].Therefore, the missionaries would target the lower-classes people as potential disciples, which led the missionaries to prefer building churches in densely populated, especially in old city residential areas.
The total population of Nanjing has been increasing generally since 1912.According to Nanjing Population statistics, the population was 269,000 in 1911, 497,526 in 1928, and then 795,955 in 1934 [21].
After 1927, with the implementation of the City Plan of Nanjing, the densely populated area expanded from the southern portion of the city to new functional districts.As shown in Figure 5, although the fourth district (residential) was still the densest area in terms of population, the second district (business) and the fifth district (cultural and educational) absorbed a large proportion of the population.
Further, because the Nationalist Government and its high-ranking government officials publicly supported Christianity, the Christians expanded on their previous missionary strategy, which had targeted people in the lower socioeconomic classes, to further include people in other classes.This adaptive missionary strategy led to the agglomeration of Christian churches in newly developed, densely populated areas such as the administrative, business, and cultural and educational districts (see Figure 4 and Table 3).
Further, because the Nationalist Government and its high-ranking government officials publicly supported Christianity, the Christians expanded on their previous missionary strategy, which had targeted people in the lower socioeconomic classes, to further include people in other classes.This adaptive missionary strategy led to the agglomeration of Christian churches in newly developed, densely populated areas such as the administrative, business, and cultural and educational districts (see Figure 4 and Table 3).As of 1936, a total of 22 churches and congregation assembly points were built in the old city of Nanjing.Among these, nine churches and assembly points were distributed across the historically densely populated areas of south Nanjing (now Hongwu Road-Zhangfu Park Area), accounting for almost a half of the total assembly points.It is evident that population density was an important factor in choosing the location of building new churches.

Along New Roads
After 1927, the Republic of China gradually built a number of roads in the city.From 1927 to 1936, the total length of newly built roads reached 9.48 km [22].Xinjiekou was the center of this urban road transportation system, and Zhongshan Road, Zhongshan South Road, Zhongshan East Road, and Hanzhong Road were the longitudinal and latitudinal axes [23].This transportation infrastructure infringed the city plans of the Ming and Qing dynasties.The continued improvement in road conditions offered good opportunities for the churches to expand along the roads and to cover a wider area.For example, following the completion of Zhongshan Road in May 1929, at a total length of 12 km, there were four newly founded churches and congregation assembly points along this road by 1936, including the Baptist Convention Church, Dazhong Bridge Gospel Church, Nanjing Army, and Hongwu Road Christian Assembly.In the same year, as many as 13 churches were distributed along both sides of the major roads, including Beijing Road, Hanzhong Road, Zhongshan Road, and Baixia Road.St Paul's Church and Mochou Road Church are good examples that they were rebuilt in 1922 and 1936, respectively, and they are well protected until today.Figure 6 shows that these churches were along major roads, and in, or close to the road intersections.It is evident that the proximity to transportation infrastructure played an important role in site selection for churches [7].As of 1936, a total of 22 churches and congregation assembly points were built in the old city of Nanjing.Among these, nine churches and assembly points were distributed across the historically densely populated areas of south Nanjing (now Hongwu Road-Zhangfu Park Area), accounting for almost a half of the total assembly points.It is evident that population density was an important factor in choosing the location of building new churches.

Along New Roads
After 1927, the Republic of China gradually built a number of roads in the city.From 1927 to 1936, the total length of newly built roads reached 9.48 km [22].Xinjiekou was the center of this urban road transportation system, and Zhongshan Road, Zhongshan South Road, Zhongshan East Road, and Hanzhong Road were the longitudinal and latitudinal axes [23].This transportation infrastructure infringed the city plans of the Ming and Qing dynasties.The continued improvement in road conditions offered good opportunities for the churches to expand along the roads and to cover a wider area.For example, following the completion of Zhongshan Road in May 1929, at a total length of 12 km, there were four newly founded churches and congregation assembly points along this road by 1936, including the Baptist Convention Church, Dazhong Bridge Gospel Church, Nanjing Army, and Hongwu Road Christian Assembly.In the same year, as many as 13 churches were distributed along both sides of the major roads, including Beijing Road, Hanzhong Road, Zhongshan Road, and Baixia Road.St Paul's Church and Mochou Road Church are good examples that they were rebuilt in 1922 and 1936, respectively, and they are well protected until today.Figure 6 shows that these churches were along major roads, and in, or close to the road intersections.It is evident that the proximity to transportation infrastructure played an important role in site selection for churches [7].

Planar Expansion (1937-1949)
During the Chinese People's War of Resistance Against Japanese Aggression, the Nanjing Christian denominations changed greatly as many foreign missionaries relocated to Chongqing with the National Government or to other locations in Sichuan Province.However, a small portion of missionaries remained in various churches in Nanjing.During the Japanese's occupation of Nanjing from 1937 to 1941, pastors and church members who stayed in Nanjing established the Nanjing Safety Zone.These individuals came from a number of churches, such as St. Paul's Church, Hanzhong Church, and City Center Church, and these churches provided shelters for thousands of refugees [24].This incident was forever remembered in Nanjing's history and became a unique memory for the citizens.After China's victory of the Chinese People's War of Resistance Against Japanese Aggression, Christianity in Nanjing experienced a brief period of smooth development.Between 1946 and 1948, six new churches were built.Again, these churches and congregation assembly points were mainly located in Xinjiekou and Drum Tower districts.A large number of churches were close to one another.The spatial structure of churches presented a planar distribution pattern in urban areas, which laid the physical foundation of the Christian landscape in the old city of Nanjing (see Table 4, Figure 7).

Planar Expansion (1937-1949)
During the Chinese People's War of Resistance Against Japanese Aggression, the Nanjing Christian denominations changed greatly as many foreign missionaries relocated to Chongqing with the National Government or to other locations in Sichuan Province.However, a small portion of missionaries remained in various churches in Nanjing.During the Japanese's occupation of Nanjing from 1937 to 1941, pastors and church members who stayed in Nanjing established the Nanjing Safety Zone.These individuals came from a number of churches, such as St. Paul's Church, Hanzhong Church, and City Center Church, and these churches provided shelters for thousands of refugees [24].This incident was forever remembered in Nanjing's history and became a unique memory for the citizens.After China's victory of the Chinese People's War of Resistance Against Japanese Aggression, Christianity in Nanjing experienced a brief period of smooth development.Between 1946 and 1948, six new churches were built.Again, these churches and congregation assembly points were mainly located in Xinjiekou and Drum Tower districts.A large number of churches were close to one another.The spatial structure of churches presented a planar distribution pattern in urban areas, which laid the physical foundation of the Christian landscape in the old city of Nanjing (see Table 4, Figure 7).4 for more information on each church.Church numbers are in accord with that in Table 4.  4 for more information on each church.Church numbers are in accord with that in Table 4. Note: See Figure 7 for specific locations of these churches.Church numbers (first column) are in accord with that in Figure 7.

Summary: Characteristics of Nanjing's Modern Christian Cultural Landscape from the Perspective of Sense of Place
The phenomenology of a place is proposed as a philosophical background in relation to Western urban planning and human geography in the 1970s [25].The concept of "place" is different to traditional understanding of urban space, as its importance is not only reflected in the material environment but also includes the relationship of the place with urban space and other complex associations with urban life.The attachment of people to a place can be described as a "sense of place" [26].Brown and Perkins described a special, strong emotional memory of a place as the primary factor for the development of a "sense of place" [27].
Relph believed that "place" comprised three different components: physical, functional, and meanings [26].Thus, a place that becomes an important site of the city is often an important carrier of the urban cultural landscape; or, it is already an important cultural landmark.In addition, a place can represent the spatial scale of the religious landscape [28].A place unites the formation of individual identity with the community's identity [29].Introducing the concept of "place" to the study of modern Nanjing's Christian cultural landscape is based on the close association of place and identify throughout history.The "place", with Christian churches as its core, brings authenticity to its cultural landscape.
The intrinsic logical connection between Christianity and the place they occupy is the landscape's impact on the functional and cultural meanings of the place, which form a complete series of cultural heritage landscape [30].It is necessary to understand the characteristics of cultural landscape from the perspective of Sense of Place.The discovery of the complex relationship between Christianity and the development of modern cities, coupled with the identification of unique characteristics of its place, would facilitate the process of finding the value of religious cultural landscape.The characteristics of Nanjing's modern Christian cultural landscape from the perspective of Sense of Place are as follows.

Vision and Structure
The concept of place contains the meanings of location and landscape [26].This concept is similar to that of space, but further includes the intrinsic meaning of man's residence, living, and behaviors [31].A place is the living space of man, and physical space plays an important role in the formation of a "place" [32].On the one hand, the physical characteristics of place are based on the heterogeneity of the church landscapes.On the other hand, they are also an integrated visual and structural expression.Hartman, in his book Models and proposed that visual expression plays an important role in replacing rituals, most notably in religious landscapes [33].For a long time, Christian churches had a strong visually symbolic meaning in Nanjing's built environment.In the 1860s, the Taiping Heavenly Kingdom's movement destroyed many buildings and streets in Nanjing, including the living houses, ancient temples and pagodas, scenic spots and Ming imperial city [34].Until that time, the ruins of the destroyed buildings and monuments could still be seen in the old city [16].However, some features of the Western architecture style such as expansive meeting space, sound construction quality, and decorative symbols on the facades made them stand out as important landmarks of the city or even for the region.Take Mochou Road Church and St. Paul's Church as examples: both buildings are well protected and in good conditions and appearance.The Mochou Road Church has a cross-shaped plane with a facade of Tudor style of England in 1600 A.D. The facade is made up of Gothic pointed arch gates and long pointed arch windows.The highest pointed arch is 17 m, making the church stand tall and straight, soaring to the sky.St. Paul's Church is Revival style which was very popular at that time.Its total area is 800 m 2 and the building height is 11 m.The façade is in Gothic style and built with polished bricks.The building costs, scales and heights are far superior to other public buildings and dwelling houses at that time.Therefore, they became Christian visual expressions together with their western architectural styles (see Figure 6).
A sacred space is a space around a fixed point or a center, whereas the secular space is a homogeneous and neutral space [35].The spatial development of modern Christian cultural landscape shows the transition from sacred space to secular space, which reflects a characteristic of modern urban landscape.
The origins of modern urban planning lie in the eagerness and desire to add a rational external order to the physical environment and society [36].In Nanjing, modern urban planning was implemented along with zoning designations and construction of road networks [37].This process was accompanied by the evolution of the Christian landscape space.
In the early years (1860-1912), the churches were mainly concentrated in the Confucius Temple (see Figure 1a) area and the south of the old city where population growth occurred mostly.In later years, although this trend continued, the spatial expansion of churches apparently increased in response to urban structural improvements.Evident trends of urban infrastructure expansion along the road systems and new functional zones could be observed.With further examination of its cause, this type of structural relationship reveals the strong associations of the religious landscape with the city's space rights.
The architect Christian Schulz argued that a place can express the spirit, value, and meaning of a rich physical space in terms of concrete spatial manifestations and structures.It can connect man with the environment and the world in a positive way [38].In Lynch's book The Image of the City, Lynch also articulated that a good city topology always embeds a variety of meanings and values during the historical progression of a city [39].Similarly, the Christian cultural landscape in Nanjing is embedded in a valuable place within a city's structure.It is important to explore and cherish the value of its pattern and structure to realize the protection and activation of the physical cultural landscape.

Function and Modernization
The 19th century is often regarded as the beginning of modernization in Chinese cities, including Nanjing [40].The dissemination and development of Christianity in Nanjing was accompanied by the process of urban modernization.In the context of colonial expansion, the introduction of Christianity to China had a strong political agenda, which also predetermined that the dissemination of Christianity was not simply a religious and cultural exchange [41].
Based on a series of missionary provisions, missionaries were granted the right to purchase properties and to construct churches, hospitals, charitable institutions, schools, and assembly halls.These properties and sites, which originally served religious activities, also complemented some of the modern city functions [42].The essence and scope of modern urban planning is that it began to focus on the lives of ordinary people, and it attempted to control the physical and social environments of daily life through rational design and policy interventions [43].
In this process, all kinds of religious spaces transcended the physicality of places, and attained a unique meaning from human lives and behaviors.According to Pred, a place is constructed by different courses of socio-economic practices [44].These courses formed the predecessors of the public utilities and infrastructure of modern Nanjing.Using education and health care facilities as an example, until April 1949 (the liberation of Nanjing), there were 29 church-run schools: two universities, eight high schools (including four girl's colleges), a senior health school, and 18 primary schools.In addition, the Nanjing Christian hospitals and clinics included four units: Drum Tower Hospital, Wesley Medical Clinic, Daosheng Clinic, and Aiqun Clinic [7].Many such facilities continued to play an important role after the establishment of the People's Government post-liberation, and most of them were serving the general public, except Christians.The continuation of this functionality reinforced the sense of "place" created by the Christian cultural landscape and expanded its scope that was originally centered on the churches.

Memory and Identity
The "sense of place" is a profound emotional connection developed by humans based on their memories and experiences of, and feelings about cultural landscape [45].After the outbreak of the Chinese People's War of Resistance Against Japanese Aggression, the Christian churches in Nanjing were involved in a historical process of local memory and reinforced the "sense of place" in Nanjing.During the period of the Japanese's occupation of Nanjing (1937Nanjing ( -1945)), church buildings and church-run schools and hospitals were areas of high concentrations of foreign missionaries due to the superior quality of their building structures.The Drum Tower, for instance, had favorable connection to urban infrastructure and sound building quality.As the Japanese regarded the churches with a certain degree of fear, the Christian denominations could form the Nanjing Safety Zone centered around Jinling University and Marin Hospital (now Drum Tower Hospital), which provided shelters for the refugees.The Nanjing Safety Zone covered an area of about 3.86 km 2 , within this zone, there were Jingling University, Jinling Women's Arts College, Jinling Theological Seminary, Jinling Middle School and Marin Hospital.The buildings of these facilities were always in good conditions and have enough space to resettle the refugees.The committee of Nanjing Safety Zone set up 25 refugee shelters in these buildings [46] (Figure 8).Until today, the well-preserved buildings in these areas are still used as settings for filming to recreate the Nanjing Massacre and related topics.It is this historical context that gives the Christian cultural landscape in Nanjing an unparalleled local memory, compared with other Chinese cities.The most obvious structural connection between memory and place is the field of physical cultural landscape [27], while the interactions of landscape and memory has shaped the local cultural characteristics and established local identity.The collective memory is both temporal and spatial.It is rooted in places that contain its memories.Cultural landscapes record the ways in which past times are intertwined in a network of intermingled memories and memorial sites [47].However, nowadays, the Nanjing Safety Zone mainly exists in the literature and films.Its original physical structure no longer exists.The protection of these cultural landscapes from the perspective of local memory and identity is urgent.

Discussion
Some scholars considered that the development of Christianity in China is actually the structural changes that occurred between universal Christianity and Chinese Christianity in a localization process [48].In this process, the development of Christianity presents a tendency to integrate universal theological ideas into the local social and cultural customs.When this process is closely The most obvious structural connection between memory and place is the field of physical cultural landscape [27], while the interactions of landscape and memory has shaped the local cultural characteristics and established local identity.The collective memory is both temporal and spatial.It is rooted in places that contain its memories.Cultural landscapes record the ways in which past times are intertwined in a network of intermingled memories and memorial sites [47].However, nowadays, the Nanjing Safety Zone mainly exists in the literature and films.Its original physical structure no longer exists.The protection of these cultural landscapes from the perspective of local memory and identity is urgent.

Discussion
Some scholars considered that the development of Christianity in China is actually the structural changes that occurred between universal Christianity and Chinese Christianity in a localization process [48].In this process, the development of Christianity presents a tendency to integrate universal theological ideas into the local social and cultural customs.When this process is closely linked with the process of urban modernization, it will provide a series of cultural landscape imprints, expressing unique religious cultures of a place.
Australians enacted the Charter for the Conservation of Places of Cultural Significance (The Burra Charter) in the 1970s, which adopted the concept of "place" to interpret cultural heritage rather than cultural relics, buildings, and sites [49].The "place" concept includes sites, areas, lands, landscapes, buildings (groups) or other constructs.At the same time, it may also include elements, contents, space, and landscapes, which further emphasizes the place's cultural importance [50].Therefore, based on the notion of activation of place, this current study facilitates the exploration in broader fields and more profound connotations for sustainable development of Nanjing's modern Christian cultural landscape.

Activation of Local Material Form
For churches built prior to 1949 in Nanjing main city, nine of them remain in use or have retained their physical structure.Among these nine churches, only two are listed as Municipal Heritage Conservation Sites.Most of the other churches were destroyed or demolished for various reasons.Some churches are located within other facilities or scenic parks.For example, Daosheng Church is located within the 12th High School of Nanjing, and the Drum Tower Church is situated within the Drum Tower Park.In addition, Xiaofen Bridge Assemblies of God Church is now the John Rabe House, listed in the National anti-Japanese War Memorial Facility and Site directory (Table 5).In addition to churches, the early establishment of Christian schools, hospitals, cultural institutions, social welfare agencies, and many other similar facilities are the predecessors of Nanjing's modern public facilities.However, most of these facilities cannot be sustained due to the lack of physical structure, and lack of awareness.In addition, the rich and important historical information retained by these facilities is no longer accessible to the general public.The theory of Place proposes a three-step process for one's appreciation of a place: the first step is primarily the recognition and identification of the physical environment; the next step is the behavioral participations; and, finally, the understanding and appreciation of a place's meanings emotionally [26].
Cresswell also noted that memorials, museums, preservation of certain buildings, plaques, inscriptions, and the designation of an entire metropolitan as a "historic site" are all examples of setting a memory into a place.The material form of a place implies that the memory is not subject to the vagaries of the psychological processes; instead, it is remembered in the landscape and becomes the public's memory [51].Therefore, the activation of the modern Nanjing's Christian cultural landscape is also the activation of the material form.It includes the activation of two aspects as follows.
Regarding the spatial activation of individual Christian material forms, the main objective is to provide material contents that can be perceived and attached to historical information.Such information could include the church construction history, development process, stories of the place, biographies, and other information.This approach can be applied to facilitate people's retrieval of memories and discovering of places.For Christian spaces that is accessible to the public, it is possible to highlight historical information through outdoor space reorganization, border reconstruction, space renovation, and landscape retrofit design.Conversely, for nonpublic Christian spaces, it is still feasible to convey locational and historical information through unified signage, outdoor information plaques, or annotations through multimedia channels.
In addition, to activate the material form of the Christian cultural landscape, it is advisable for Nanjing to adopt the concept of "heritage corridor", for instance, Cultural Heritage Corridor of Modern Christianity.The heritage corridor is a linear landscape feature with a collection of special cultural resources.It is a continuous tourist trail that connects and integrates historical and cultural heritage resources.Specifically, this heritage corridor has four main elements: green corridor, walking trail, heritage, and guide system [52].The green corridor is designed to provide an appropriate boundary and backdrop for the internal religious cultural landscapes or to emphasize the continuity of the heritage corridor as a whole.Because most protected churches are located in older urban areas that lack leisure space, the heritage corridor provides connected walkway systems and open meeting spaces for local residents, forming unique community interaction spaces.There, local residents can walk, play, talk, and exercise.These daily activities afford local residents increased opportunities to sense the religious history of these sites, allowing them to form multisensorial impressions of these areas [53].
The guide system can combine the significance and connotations of the structural evolution of Nanjing's modern Christian culture.This guide system can also provide talks on different topics and in various formats, such as topics on religious development, urban planning, road construction, and social transformation.It is also possible to organize self-guided tours for tourists, who can derive a real feeling of the complete "local-context structure" through this walking tour.Based on structural reorganization, it is possible to establish religious cultural preservation organizations and volunteer systems that can draw cognitive maps with the help of community residents.In addition, these organizations can regularly conduct community learning and community decision-making meetings to discuss heritage preservation and the construction of "heritage corridor".Because most of the existing Christian landscapes are located in the densely populated community, there are many businessmen live and do business here.They can also take part in the construction of community base on the protection of Christian landscape.Hence, the final implementation can achieve the balance between creating economic prosperity and protecting cultural landscape heritage.These activities will help establish links and ties between individuals and sites, and between individuals and groups.Finally, a collective awareness of these sites will be formed, allowing for intergenerational transfers of culture, which will further strengthen this collective consciousness.It is suggested to incorporate the modern Christian cultural heritage walking tour into the Ancient Capital Protection Project, thereby helping Nanjing residents to regain the precious local material form.In addition, this project would be an asset to the historical features of the Republic of China.

Activation of the Local Functions
Some scholars pointed out that, in a modern society, it is impossible to confine religion to a small private space [54,55].In public life, it will play just as important a role as in personal beliefs [56].Historically, in Nanjing, Christianity also promoted religious permeates through citizens' lives and the construction of modern city functions, which also constituted important features of modern Christian cultural landscape.
Nowadays, these Christian cultural landscapes carry different functions in the city life in Nanjing.The first part includes churches that are on the list of Municipal Heritage Conservation Sites are highly popular.They are not only responsible for religious functions, such as Sunday service, Bible study, youth gathering, but also take certain responsibilities in the community, such as hosting children's summer camps, choirs and certain public memorial events including the Nanjing Massacre Victims National Memorial Day (13 December).In addition, these important churches are well-known scenic spots in Nanjing.They are extremely crowded in western festivals, such as Thanksgiving Christmas holidays.Therefore, these Christian cultural landscapes witnessed the influence of western religion over the course of Nanjing's development.The second part consists of some other historical churches which remain in use, while less known to ordinary folks after their name changes, or due to the poor protections of their physical structure.The last part encompasses a series of schools and public facilities which were built by Christian churches.Although these facilities still carry important city functions, few people know about their history and their relationships with the Christian culture.
Activation of the local city function is an important component in the protection of modern Christian cultural landscape in Nanjing.Activation of the local function should include local-function backtracking and local-function reconstruction.For example, the educational institutions founded by the Church prior to 1949, and which continue to run, comprise 15 primary schools and seven high schools.In fact, many well-known schools had Christian-run schools as their predecessors.For instance, the American Methodist Episcopal Church established the private high school of Jinling University in 1887, which became the present Nanjing City Jingling High School.Furthermore, in 1896, the American Christian Association founded the private primary school affiliated with the Chinese High School for Girls, which later became the present Drum Tower Primary School.Thus, local-function backtracking is aimed at helping recover the historical memories of these important places.The historical memories can be publicly archived through photography, surveying and mapping, audio and/or video recording, and 3D modeling.It is also possible to set up a small exhibition room on site or a special exhibition hall at the same place to facilitate local-function backtracking.
Reconstruction of local function relies on the implantation of new functions the assimilation of these functions into the city's urban life.Local cultural characteristics are achieved through urban life.However, the construction of local cultural characteristics should not be confined to the development of superficial tourism products; but rather, it should be an activation of the cultural industry, that combines modern Nanjing's Christianity history and its contemporary social functions.For example, the activation can be based on the educational functions of altruism, the promotion of anti-war and historical retrospective functions, or be based on the dissemination of religious art and cultural educational functions.
It is advisable to work with the community to set up public classrooms inside the existing Christian spaces and to achieve regular operations of cultural industry via themed-activity days and tourist-experience days.Effort should be made to align urban functions and spaces with the following aspects: zoning, industrial development, landscape design, and open space planning design, and management.It is also advisable to encourage residents to participate in the evaluation process of the protection and reconstruction planning.Hence, residents' interest in the city's history can be cultivated by the activation of the local function, thereby inspiring the public to cherish this period of unique history in Nanjing.

Activation of Historical Meanings
The heterogeneity of a city is a result of the different stages the city has experienced during its developmental process.During the Chinese People's War of Resistance Against Japanese Aggression, the tragic massacre experienced by Nanjing, together with the deep humanitarian reliefs subsequently received, are important historical moments that should never be forgotten.The "Nanjing Safety Zone" and the historical events that occurred in this Zone bestowed this space a historical significance.
The activation of local historical significance emphasizes the use of material form and space, via methods that can provide realistic feelings and daily experience to reproduce the meaning of local significance.Most of the Christian cultural spaces, including the "Nanjing Safety Zone" that carries such historical significance, are scattered in the densely populated old city of Nanjing.These spaces are presently parts of the vibrant urban daily life.Thus, the concept of eco-museum and community museum can be used to create open-boarder city museums in order to activate the local historical significance [57].Greenhill once commented, architecture is used to imagine modern museums.The museums of the future will be imagined on the basis of process or experience [58].The museum should go beyond its walls and be exposed to the community.
For example, the Museum of the Nanjing Safety Zone could be rebuilt based on important "places".In these places, a unified design showcasing the city system could be planned together with an educational route, open exhibitions, public classrooms, and activity clubs.Alternatively, based on the existing walks, a historical sightseeing route could be set up by applying designs unified in color and material.Public classrooms and clubs can be set up in association with important sites along the route.These spaces are also good places for field trips of elementary and middle schools.The injection of abundant and fresh elements can help to evoke the public's curiosity, interest, and spirit of exploration.Thus, public awareness and appreciation of history can be generated.Moreover, future museums would emphasize a diverse array of experiences that are universal, social, lifelong, intuitiveness, richness, openness, autonomy, and pleasant.The methods aforementioned would disseminate historical significance of places, facilitate the public's gaining a sense of intimacy and belonging to local meanings, and thereby enable the residents to define their place in the city through a regional consciousness.

Conclusions and Future Prospects
The production, development and evolution of modern Christian landscape in Nanjing interacted deeply with the social processes and space development of the city.It is necessary to study these interactions to gain a profound understanding of the characteristics and value of Nanjing's modern Christian landscape.The Christian landscapes are important elements that construct the special places in Nanjing.A strong sense-of-place is formed through three components: vision and structure, function and modernization, and memory and identity.The protections of the Christian landscapes should include the activation of material form, local functions and historical meanings in order to achieve sustainability.
Local activation strategies rooted in local historical research can help certain parts of the cultural landscape that are experiencing gradual decline to achieve lasting urban vitality by safeguarding their physical space.For the sustainable development of the religious cultural landscape, further research in the following areas is called for.First, there is an urgent need to conduct a comprehensive survey of Nanjing religious cultural landscape.This would include creating a registrar of valued religious and cultural landscape sites, classifying them, assessing the current status and value of each, and conducting further cultural significance research.Second, there is an urgent need to conduct further research on the laws and regulations for the protection and sustainable development of religious cultural landscape's remains.Currently, Nanjing has yet to launch such laws and regulations that specifically address the protection of religious cultural landscape.A systematic legal protection mechanism includes each of the following components: urban master plan, urban growth management plan, urban design standards, urban historical district, and urban management guidelines.
Finally, there is an urgent need for research on the methods to protect and sustain the value of Nanjing's religious cultural landscape.The top priority to protect these religious cultural landscape is to protect their historical features.This requires a team of experts to conduct specialized research with sound approaches.Research must focus on protecting key elements of each category of the historical features.In addition to the protection of the material, research is needed to study the expression of the cultural and historical meanings through the design of landscape, and provide diverse spaces to urban residents.
This paper adopts descriptive and extensible literature review methods and map analysis methods to provide a strategy for research related to the historical value and spatial evolution of religious cultural landscape heritage.Next, based on historical periods, this paper summarizes the spatial distribution characteristics of religious cultural landscape heritage at different historical periods, and establishes spatial relationships between these periods within the city of Nanjing.Based on the above research, this paper summarizes the characteristics of this type of cultural landscape heritage on the basis of establishing a local feeling, from the three perspectives of image, structure, and identity.Finally, this paper proposes a sustainable heritage revitalization strategy.The above research combines results of research in a variety of academic fields, and innovatively proposes a practicable methodological system suitable for use in the field of landscape planning.
Future research is called for to continue conducting empirical and theoretical explorations based on the above results.Empirical research would include specific practical policy plan strategies and practical case studies.Theoretical research would continue to improve culture-based sustainable heritage preservation methodological systems, and would expand to include other types of cultural landscape heritage.At the same time, future studies may include additional quantitative analysis, such as the use of memory maps and big data methods, to investigate the religious cultural landscape experiences of communities, and to conduct surveys on landscape memory.
Finally, this study mainly focused on Christian landscape development prior to 1949 since this period is of paramount importance in the formation of memory of place in Nanjing.Future studies should also look into later phases for sustained growth and appreciation of this cultural phenomenon and heritage of Christian landscape.

Figure 1 .
Figure 1.(a) Nanjing main city with significant cultural and environmental components; (b) key map; and (c) current municipal boundary.

Figure 1 .
Figure 1.(a) Nanjing main city with significant cultural and environmental components; (b) key map; and (c) current municipal boundary.

Figure 2 .
Figure 2. Location of churches built from 1860 to 1912, Nanjing, China (historical map of Nanjing, China (1910), used with permission from Nanjing Publish).Note: SeeTable 2 for more information on each church.Church numbers are in accord with that in Table 2.

Figure 2 .
Figure 2. Location of churches built from 1860 to 1912, Nanjing, China (historical map of Nanjing, China (1910), used with permission from Nanjing Publish).Note: SeeTable 2 for more information on each church.Church numbers are in accord with that in Table 2.

Figure 3 .
Figure 3. Location of churches built from 1912 to 1937, Nanjing, China (historical map of Nanjing, China (1932), used with permission from Nanjing Publish).Note: See Table3for more information on each church.Church numbers are in accord with that in Table3.

Figure 3 .
Figure 3. Location of churches built from 1912 to 1937, Nanjing, China (historical map of Nanjing, China (1932), used with permission from Nanjing Publish).Note: See Table3for more information on each church.Church numbers are in accord with that in Table3.

Figure 4 .
Figure 4. Location of churches and city functional districts in 1936, Nanjing, China.See Legend for district numbers.

Figure 4 .
Figure 4. Location of churches and city functional districts in 1936, Nanjing, China.See Legend for district numbers.

Figure 6 .
Figure 6.The relationship between the location of churches and roads, Nanjing, China: (a) location of Mochou Road Church; and (b) location of St. Paul's Church.

Figure 6 .
Figure 6.The relationship between the location of churches and roads, Nanjing, China: (a) location of Mochou Road Church; and (b) location of St. Paul's Church.

Sustainability 2017, 9 , 2155 14 of 25 Figure 7 .
Figure 7. Location of churches built from 1937 to 1949, Nanjing, China (historical map of Nanjing, China (1946), used with permission from Nanjing Publish).Note: See Table4for more information on each church.Church numbers are in accord with that in Table4.

Figure 7 .
Figure 7. Location of churches built from 1937 to 1949, Nanjing, China (historical map of Nanjing, China (1946), used with permission from Nanjing Publish).Note: See Table4for more information on each church.Church numbers are in accord with that in Table4.

Figure 8 .
Figure 8.The Safety Zone and Churches in 1937, Nanjing, China.

Figure 8 .
Figure 8.The Safety Zone and Churches in 1937, Nanjing, China.

Table 1 .
Population of Christians from 1893 to 1950 *.

Table 2 .
Churches built in Nanjing main city from 1860 to 1912 *.

Table 3 .
Churches built in Nanjing main city from 1912 to 1937 *.

Table 4 .
Churches built in Nanjing main city from 1937 to 1949 *.

Table 5 .
Churches listed for protection under national and municipal levels.