In 1847, a strong defensive wall was built around the fort. Both the wall and the city went through a great deal of turmoil over the years.
After Japan's surrender in WWII, China decided to assert it's power over the city. Refugees began to pour into Kowloon and squatters took over the city by 1947.
In the following decades, the city became a den of brothels, gambling, crime and gang activity.
A series of police raids failed to clean up the city. In 1987, the government did a comprehensive survey and found that 33,000 people were living within the city's walls.
With an area of 0.0102 square miles, this put the population density at 3,250,000 people per square mile.
