Kowloon Walled City was originally a garrison town built by the Qing government in 1847 as a military outpost occupied by several hundred soldiers to reinforce the coastal defence of the region. The City wall was built with large granite slabs and incorporated six watch towers and four gateways. The South Gate was officially recognised as the "main gate". During the Japanese Occupation, the wall was completely torn down to provide material to extend Kai Tak Airport. In 1987, the government decided to demolish and replace the Walled City by a park. Archaeological investigations were conducted in the course of demolition of the buildings. Archaeologists and found that foundations of the original South and East Gates were particularly well preserved. The most important discovery was the two stone plaques bearing the characters "South Gate" and "Kowloon Walled City" of the original South Gate. Consequently, the Government decided to preserve the remnants of the South Gate in-situ for display to the public.