Note that the walled city is just a small part of Kowloon district. The famous Kai Tak Airport was also in Kowloon (now converted into an event space), where airliners flew scarily close to buildings on final approach.
I lived in Hong Kong just under 10 years, and a friend of a friend grew up in the walled city.
According to Wikipedia, China actually handed over sovereignty of Kowloon to the British to facilitate demolishing it. They must have really hated the place.
I lived in Hong Kong just under 10 years, and a friend of a friend grew up in the walled city.