Podcast:99% Invisible Published On: Mon Nov 19 2012 Description: Kowloon Walled City was the densest place in the world, ever. By its peak in the 1990s, the 6.5 acre Kowloon Walled City was home to at least 33,000 people (with estimates of up to 50,000). That’s a population density … Continue reading → Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to ad-free new episodes and get exclusive access to bonus content.