New York City is one of the most densely populated cities in the United States, with about 28,000 people per square mile.

Now double that. Then double that about six times. With its 33,000 residents crammed into a six-and-a-half-acre space, the Hong Kong settlement known as Kowloon Walled City boasted a population density of about 3.25 million people per square mile (as of 1987). The space was so tightly packed that light barely reached the ground — even in the middle of the day. And it’s rumored that residents could cross the entire city in any direction without touching the ground, thanks to an extensive network of catwalks and staircases.

Kowloon Walled City began as a Chinese trading outpost (perhaps as early as the 10th century), then became a military base in 1668. The area changed hands over the centuries in ways that might even confuse dedicated history students — from the Qing dynasty to Britain, then to a group of Christians during the Taiping Rebellion, then back to a Qing ruler, back to Britain, on to Japan, and then back to China after World War II. From the early 1970s to the late 1980s, the population of Kowloon more than tripled. Architecture mirrored this expansion, as nearly every building (except one yamen — or administrative office building — at the city’s center) grew to a height of 10 to 14 stories.

As the population ballooned and the presence of law enforcement shrank, the settlement became home both to organized crime and to a tightly-knit and supportive community. According to a <a href="http://www.amazon.com/City-Darkness-Life-Kowloon-Walled/dp/1873200137){: target="_blank" rel="nofollow" }, many residents hung out on the city’s rooftops — these were reportedly a favorite place for kids to do their [homework](https://www.noodle.com/topics/homework-help" target="_blank">book about Kowloon after school.

Kowloon was demolished in 1992 (largely due to concerns about crime, sanitation, and public health), but you can visit the park that now exists where the mass of buildings once stood.

If you’re interested in learning more about Kowloon Walled City, the complicated history of Hong Kong, urban architecture, or even speaking Cantonese, Noodle has you covered. Check out our college search tool, which allows you to filter results by major to find the right fit for you.