Kowloon Walled City Enclave, Kowloon, Hong Kong, China

The Walled City was located in what became known as the Kowloon City area of Kowloon. In spite of its transformation from a fort into an urban enclave, the Walled City retained the same basic layout. The original fort was built on a slope and consisted of a 6.5-acre (0.3 km2; 0.1 sq mi) plot measuring about 210 by 120 m (700 by 400 ft). The stone wall surrounding it had four entrances and measured 4 m (13 ft) tall and 4.6 m (15 ft) thick before it was dismantled in 1943.
Construction surged dramatically during the 1960s and 1970s, until the formerly low-rise City consisted almost entirely of buildings with 10 stories or more (with the notable exception of the Yamen in its center). However, due to the Kai Tak Airport's position 0.8 km (0.5 mi) south of the City, buildings did not exceed 14 stories. The two-story Sai Tau Tsuen settlement bordered the Walled City to the south and west until it was cleared in 1985 and replaced with Carpenter Road Park.
The City's dozens of alleyways were often only 1–2 m (3.3–6.6 ft) wide, and had poor lighting and drainage. An informal network of staircases and passageways also formed on upper levels, which was so extensive that one could travel north to south through the entire City without ever touching solid ground. Construction in the City went unregulated, and most of the roughly 350 buildings were built with poor foundations and few or no utilities. Because apartments were so small—about 60% were 23 m2 (250 sq ft)—space was maximized with wider upper floors, caged balconies, and rooftop additions. Roofs in the City were full of television antennas, clotheslines, water tanks, and garbage, and could be crossed using a series of ladders.