East Kowloon's coastline was once a series of salt pans, with the earliest of them dating back to the Sung dynasty between 960-1279. It was a lucrative monopoly of the Imperial government, with salt being produced from the bays between Tsim Sha Tsui, Kowloon City, and To Kwa Wan and Tseung Kwan O. Kowloon City's rich historical background is largely linked to its strategic military and political value. The Qing government (1644-1912) built a small fort at the head of the beach (centre of Kowloon Bay) in 1810, reinstating the importance of the area to China's maritime defence. The fort's purpose was to defend Lei Yue Mun, Kowloon Bay, Hung Hom and Tsim Sha Tsui against pirates or foreign invaders. Of even more importance to local defences was the walled garrison city, later known as Kowloon Walled City. The British had already occupied Hong Kong Island in 1841 and, in response, the Qing authorities built this imposing garrison city, protected by massive stone walls. It was designed to serve as a military nerve centre and headquarters for Imperial officials in what had become a very sensitive area. The Kowloon Walled City's design followed traditional architectural lines of fortresses. Dotted along the walls that enclosed the area were six watchtowers and four gates, which were closed and guarded each night. The enclosed area measured about 6.5 acres. The interior was dominated by the Yamen - offices of the Commodore of the Dapeng Brigade, and the Kowloon Assistant Military Inspectorate. Nearby were more than 10 military buildings, including soldiers' quarters, gunpowder and weapons stores. The defences included canons set in battlements along the wall - two of which were subsequently unearthed and are now on display at the site today. Around the military establishment, civilian dwellings sprang up, as increasing numbers of people sought safety in the Walled City. Vegetables were planted around the Walled City to provide food for the occupants, along with fish brought by fishermen to the nearby stonework pier that was specially built to receive Mandarins arriving by junk from Guangzhou or nearby ports. Originally, 150 soldiers were stationed there, but the situation changed as the British continued to nibble away at the Kowloon Peninsula, grabbing more territory. As a result, by 1898/99, more than 500 troops had been squeezed into the Walled City along with a growing number of civilians seeking safety. Britain had tightened the net on the Walled City by taking possession of the Kowloon Peninsula in 1861, and leasing the New Territories for 99 years starting from 1898. Whether China retained sovereignty of the Walled City, or the land belonged to Britain, was a matter of dispute for many decades. However, the mainland clung to its toehold of Hong Kong for as long as possible. This sowed the seeds of the enclave's deterioration, becoming a festering crime-ridden slum, especially after the Japanese occupation of 1941-45. During the occupation, the old wall was torn down and used to fill an inlet near what was then the Kai Tak airfield. Later, when Kai Tak Airport was being built, much of the large hillside overlooking the Walled City was flattened to extend the runway into the harbour. Little remained of the original city except the foundations - two carved granite plaques from the original south gate - a flagstone path next to a drainage ditch running along the foot of the inner wall, old canons, stone lintels and column bases. Years later, and particularly as refugees flooded through Hong Kong's borders following the Communist victory in 1949, thousands of homeless people jammed into the Walled City - again with the aim of seeking refuge. With neither the Chinese nor British authorities in control, conditions in the Walled City turned for the worse. Opportunists grabbed control of vacant sites and sold them to unscrupulous developers, who threw up residential buildings as high as six storeys - but without any foundations, lifts or other facilities besides stairways and electricity. The Walled City degenerated into a maze of dank and dirty alleyways. The ground-floor premises became notorious nests of drug dens, criminal hideouts, vice dens and a haven for cheap, unlicensed dentists. It continued to exist until the signing of the Sino-British Joint Declaration in 1984 when the issue was finally resolved. In 1987, the Hong Kong government announced that it would tear down Kowloon Walled City and build the Kowloon Walled City Park. Construction of the park was completed in 1995.