Photographer Andy Yeung has called Hong Kong home since birth, but it took a trip away to spark the idea for Urban Jungle, his captivating series that captures aerial views of the city’s jam-packed skyline. As he descended on the metropolis on a returning flight, he was struck by the staggering panorama of high-rises crammed up against one another. The bird’s-eye perspective seemed to illustrate how it feels to live in one of the world’s most densely populated environments. Hong Kong is, in fact, about as crowded as a city can get, with about 68,400 residents per square mile. (For comparison, consider that New York clocks in at a mere 4,500.) Necessarily, that means it’s stuffed with skyscrapers—it has more buildings taller than 500 feet than any other metropolis on earth, many of which Yeung photographed using a drone over the span of two months.