Using Fort Precincts as Urban Green Lungs: Sion, Thane and Ghodbunder Forts

Using Fort Precincts as Urban Green Lungs: Sion, Thane and Ghodbunder Forts

Résumé en français

L'archipel de Bombay a pris de l'importance sous la domination portugaise et a prospéré sous la domination britannique. Les deux puissances coloniales, ainsi que les Marathas, ont construit de nombreux forts et citadelles dans la région pour se défendre. Cependant, une fois la domination britannique établie, Bombay est devenue un centre commercial prospère sous l'égide de la Compagnie des Indes orientales. Les forts ont perdu leur importance stratégique et la poldérisation a encore modifié leur situation.

Aujourd'hui, de nombreuses enceintes de forts sont méconnues et étranglées par le développement urbain. Compte tenu de la rareté des espaces ouverts dans la ville, ce document plaide en faveur de la préservation du patrimoine naturel des enceintes des forts situées dans le tissu urbain et de leur réaffectation, grâce à une intervention paysagère sensible, pour en faire des espaces sûrs, accessibles et inclusifs. L'intervention paysagère peut être utilisée comme un outil pour s'engager avec la communauté et attirer de nouveaux acteurs afin de garantir l'importance contemporaine de ces enceintes sans compromettre les valeurs patrimoniales.

The Bombay archipelago rose to prominence under Portuguese rule and thrived during British dominion. Both colonial powers along with the Marathas built numerous forts and citadels in the region for defense. However, once the British rule was established, Bombay became a prosperous trade center under the East India Company. The forts lost their strategic importance while land reclamation further changed their setting. Today, many fort precincts are unrecognised and strangled by urban development. Given the scarcity of open spaces in the city, the paper makes a case for the preserving the natural heritage of fort precincts situated within the urban fabric along with repurposing them through sensitive landscape intervention into safe, accessible, and inclusive spaces. The landscape intervention can be used as a tool for engaging with the community and attracting new stakeholders to ensure contemporary significance of these precincts without compromising on the heritage values.


The thriving metropolis of Mumbai  (Mumbai city and Mumbai suburban district) which lies on the west coast of India is the financial capital of the country and also one of the most important centres of commerce globally. The Arabian Sea forms the western and southern boundary of the city while the Thane creek lies on the eastern side. The city of Thane and Mira Bhayandar, a part of the Mumbai Metropolitan region  (MMR) lie on the north of Mumbai. The Ulhas River forms the natural boundary further north and meets the Arabian see at the Vasai creek.

Figure 1: Location of Mumbai  (Source: Author)
Figure 2: Metropolis of Mumbai and its immediate surroundings (Source - Google Earth, Adapted by Author)

Mumbai city mainly consists of what was earlier the Bombay archipelago . On the north of the Bombay archipelago was Sashti Island, later known by the name Salsette, along with a few smaller islands (referred to here as the Salsette group of islands). The Mumbai suburban district city along with the cities of Thane and Mira Bhayander are situated on the then Salette group of islands. The present-day continuous land mass of Mumbai and neighbouring cities of Thane and Mira Bhayander is a result of a massive reclamation project which was undertaken from the mid-eighteenth century and continued for many decades later.  

Figure 3: Bombay archipelago and Salsette group of islands (Source: Adapted by Author)

Understanding Bombay's geographical layout is vital for two main reasons. Firstly, many port cities in the vicinity of the Bombay archipelago thrived historically due to their natural harbours and navigable rivers, facilitating trade. Unlike these ancient ports, Bombay gained prominence later when the Portuguese handed it to the British, who leased it to the East India Company (EIA). The EIA effectively utilised its geographical advantages. Additionally, the Bombay archipelago's changing landmass, submerged during high tide while accessible otherwise, led to varying interpretations of its area (Kamath, 2000; Riding, 2018). This disparity in interpretation holds significance, as elaborated later in the paper.

The strategic significance of this location rendered it as a perpetual battleground with different rulers competing for dominance over the region across time. While ancient texts document power struggles among numerous dynasties, few remnants of their defensive structures endure today. However, it's the history post-16th century CE that bears relevance to the current discourse.

Forts of Bombay and Salsette: Historical Context

Following the rule of various dynasties, the region of Bombay and its surroundings was ceded to the Portuguese in the 16th century who established their capital for the North Province at Bacaim/Bassein (modern-day Vasai), gaining full control over Salsette and the Bombay archipelago. During their rule over the area, the Portuguese faced persistent challenges from adversaries like the Gujarat Sultanate, Mughals, Marathas, British, and other global and local powers. Consequently, they established strong defense mechanisms, including forts (Bassein, Casa da Orta (Bombay Castle), Versova (Madh), Cacabe de Tanna (Godbunder), Tanna (Thane), Bandorá (Bandra), and Dongri, etc), watchtowers, bastions, and outposts, which still exist today, albeit in neglected condition (Thakare,2013a). Additionally, the Portuguese also reinforced existing forts like Mahim, Karnala, and Belapur upon gaining control of the region. These interconnected defense structures played a crucial role in repelling assaults from rival powers, enabling the Portuguese to maintain dominion over this region for over a century.

The marriage treaty between Charles II of England and Catherine of Braganza of Portugal in 1661 CE led to transfer of Bombay to the British Empire, who then leased the region to the East India Company (EIC) in 1668 CE. However, this transfer of power was not smooth, as discrepancies in geographical definitions, particularly regarding seasonal submergence of land, led to enduring tension between the Portuguese and the British in subsequent years.

The English delegation who arrived in 1662 CE perceived the map provided by the Portuguese during negotiations as misleading. They interpreted the map to suggest that Bombay included the area from the bay to the north up to Bassein, extending eastward to Trombay. This implied that the region south of Bassein creek, located 30 km north of Bombay, was depicted as a single island. This discrepancy in interpretation heightened tensions between the two powers. (Kamath, 2000; Riding, 2018).

The British eventually accepted the Portuguese viceroy's definitions of Bombay. Thus, the Bombay archipelago, excluding Mahim, became a part of the British territory leaving Mahim and Salsette group under Portuguese control. Now the British had to defend their territory against Portuguese and various other local and foreign powers. Conflicts persisted for over a century, prompting the British to build multiple defense structures across the Bombay archipelago, including forts at Sion, Riwa, Fort George, Worli, Sewri and Mazgaon, among others.

Figure 4: Forts in and around the Bombay archipelago and the Salsette group of islands (Source: Adapted by Author)

In 1737 CE, the Marathas, led by Chimaji Appa, captured Bassein fort, eventually acquiring much of the Portuguese Northern province. They fortified their position by building forts, reinforcing some of the existing ones. Consequently, Bombay archipelago and Salsette group became dotted with defensive installations, including forts from preceding dynasties and those built later by the Portuguese, British, and Marathas.

18th century onward, two significant events reshaped the relevance of these defense structures. Firstly, EIC gained control of territory from the Marathas, including Salsette island, leading to a decline in the fort’s importance as the struggle for supremacy in the region ended. Secondly, starting in the early 18th century, the EIC initiated a large-scale land reclamation project within the Bombay archipelago and later the Salsette group, continuing for several decades. These reclamation endeavors significantly altered the natural landscape surrounding some of these forts, thus reducing their relevance due to changes in both political and natural landscapes.

Figure 5: Forts in and around the Mumbai, Thane and Mira Bhayandar (Source: Google Earth, Author)

Mumbai,Thane and Mira Bhayander: Present Day Scenario

Following independence, Bombay saw a rapid influx of migrants from across the country seeking better opportunities, putting immense pressure on land resources. The concept of New Bombay was conceived to alleviate land constraints within the city limits. However, Mumbai still struggles with high population density.

Mumbai currently provides only 1.24 square meters of accessible open space per person, significantly lower than most major cities in India (Rajadhyaksha, 2012; Navya, 2016; Virani 2021) and far below the global standard of 20 square meters per capita. Neighbouring cities like Thane and Mira Bhayander offer comparatively higher levels of open space which however are under threat due to rapid urbanization.

The above-mentioned statistics underscore the seriousness of the situation. Countering the adverse effects of rapid urbanisation, the fort precincts within urban areas can play a significant role.

These historical landmarks serve a dual purpose: providing much-needed open spaces in dense urban areas and re-establishing a connection to the city's heritage. Examining three examples of fort precincts can further elucidate this concept.

Sion, Thane and Ghodbunder forts as case examples

The Sion Fort was constructed between 1669 and 1677 CE as a defensive stronghold against Portuguese and Maratha forces on the northern edge of Parel Island. Positioned strategically atop a natural hillock, the fort provided vantage points for monitoring Thane Creek, Mahim Island, and the Salsette region. This allowed the EIC to safeguard their territory effectively.

Today, Sion Fort is nestled inconspicuously amidst the bustling heart of Mumbai. Surrounded by high-rise buildings and a high traffic road on its two sides, it is perceived as a patch of wilderness amid the urban chaos. Despite its historical significance, the fort remains disconnected from the larger fabric of the city, primarily accessed by the immediate neighbourhood. Notified as a heritage structure, the hillock is a combination wilderness on the hillock as well as curated landscapes at the base of the fort. With a total green cover of about 3.87 hectares, the naturally occurring vegetation includes a combination of native species such as the Neem (Azadirachta indica), Jackfruit (Artocarpus heterophyllus), Mango (Mangifera indica), native palms such as Toddy (Borassus flabellifer), Coconut (Cocos nucifera) along with non-native plants like African Tulip (Spathodea campanulate) etc. Amorphophallus commuatus, which falls in the threatened category of IUCN Red List species has also been observed here (Stalin et al., 2022)

Figures 6, 7 and 8: Sion Fort precinct (Source: Attula M.)

The second case study, Thane Fort, formerly "Kasabe De Tana" and later known as "Hirkot," served as a stronghold under Portuguese rule. Strategically positioned overlooking Thane Creek near the confluence of the Ulhas River, its natural surroundings of wetlands and dense mangrove forests enhanced its defensive capabilities. Captured by the Marathas around 1738 CE, it was reinforced before falling under British control in 1744 CE. By the mid-19th century, it had been repurposed as the Thane Central Jail, where many freedom fighters were imprisoned and sentenced to death during India's struggle for independence.

Figures 9, 10 and 11: Ghodbunder Fort precinct (Source - Gayatri N.)

Today, the Thane Fort precinct houses the Thane Central Jail, and is partially enclosed by high walls, making it inaccessible to the general public and obscuring its significance and history from public memory. Rapid geographical changes in the fort's surroundings, including land reclamation and the narrowing of the creek, have dramatically altered its original setting. The fort is now landlocked, separated from the Thane creek by a busy traffic road and an emerging flyover. On its west, the fort adjoins a freshwater lake. The fort precinct  is a repository  totem species such as Peepal (Ficus religiosa), Banyan (Ficus benghalensis) and native trees including Neem (Azadirachta indica), Jackfruit (Artocarpus heterophyllus) etc

The third case study is the Ghodbunder Fort, initially constructed by the Portuguese in the mid-16th century as Cacabe de Tanna. The name, Ghodbunder, is derived from its historical function as a trading and resting place for horses ("ghoda" in the local language). Positioned atop a hill near the Vasai creek, the fort held strategic importance due to its commanding view and proximity to the Vasai Fort. Under Portuguese control until 1737 CE, it was later captured and fortified by the Marathas. In 1818, the EIC seized control and converted it into a local administrative office.

Today, despite renovation efforts by the Archaeological Survey of India (ASI), the larger precinct remains neglected and also faces encroachment. The fort still offers a breathtaking view of Vasai Creek and the lands across the Ulhas River, serving as a reminder of its historical significance and the strategic acumen of the Portuguese in selecting its location. With the thriving mangrove forest at its base, including both native species as well as non-native species, the hillock is a repository of some fine tree specimens. One unique non-native keystone tree specie found in the precinct is the African Baobab tree (Adansonia digitata) probably introduced by the Portuguese in this precinct.

Table: 1 (Source: Author)

The three examples discussed represent different contexts. Recent discussions have focused on beautifying the Sion Fort precinct (Jain, 2011), converting Thane Fort into a museum(Menon, 2018; Natu, 2018) by shifting the Thane central jail to another location and upgrading Ghodbunder Fort (Mehta, 2014)  for annual cultural festivals. However much remains to be done. Though the ASI  has been actively working on the repair, upgrading and maintenance of the built heritage of the fort precinct, the natural heritage and curation of open spaces within the fort precinct still remain unexplored.

The Way Forward

In a city lacking in open spaces, the fort precincts can provide for an open space but also serve as repositories for native, totem, threatened species as well as unique species from around the world. Rather than adopting a conventional approach, these precincts provide an opportunity for sensitive landscape intervention to transform the precincts into safe, accessible, and inclusive spaces along with engaging the community. The landscape intervention can be used as a tool for attracting new stakeholders to ensure contemporary significance of these precincts without compromising on the heritage values (Madan, 2017)

A holistic strategy is required to intervene in the fort precincts taking clues from the historical and cultural context,

• to recognise the significance and distinctiveness of natural heritage for preservation, adaptation, and repurposing

• to identify the diverse groups of users spanning various social, economic, and cultural backgrounds

• to uncover avenues for generation of awareness, education, entertainment, employment etc

• and address both conflicts and potential benefits arising from these considerations. (Madan, 2017)

The case of Sion fort has been further explored through the schematic site plan created based on the above framework. By curating open spaces along the existing trail within the wilderness and around the fort ruins, the design explores the existing biodiversity through spaces to linger, reflect and pause. The pause points are curated taking into consideration the existing views towards the Thane creek as well as towards the fort ruins. At the same time, they allow for people to gather, meet and have small discussions. Interesting signage about the history, as well as biodiversity along the path and at the pause points, further enhances the experience. Additionally, a ramp has been introduced for universal accessibility.

These small but sensible interventions would not only strengthen the connection between the neighbourhood and the precinct but can act as magnets to attract more city dwellers, creating a sense of connect with these guardians of the past.

Figure 12: Sion Fort and its context (Source: Google Earth)
Figure 13: Schematic layout of landscape intervention at Sion Fort (Source: Author)


In urban areas where open spaces are scarce, fort precincts hold the potential to serve not only as green havens but also as embodiments of shared historical narratives. By drawing inspiration from both past and present contexts, and employing sensitive landscape interventions that blend preservation, adaptation, and repurposing, these fort precincts can evolve into focal points that attract both city residents and tourists, weaving together past and present in the collective consciousness. This transformation can foster a sense of ownership and social responsibility towards this heritage, further bolstered by initiatives aimed at raising awareness, creating employment opportunities, and enhancing capacity within local communities surrounding the fort precincts.


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