The Regent International apartment building in Hangzhou, China, is famous for having a number of inhabitants comparable to a small town, around 20,000 people.

Located in Qianjiang Century City, Hangzhou’s central business district, the S-shaped Regent International was originally designed as a luxury hotel, but was subsequently converted into a colossal apartment building, with the rooms turned into thousands of high-end residential apartments. The impressive building is 206 m tall and has 36 to 39 floors, depending on what you’re side of it you’re on, and as any self-contained community, features a variety of amenities and businesses, like a giant food court for its tens of thousands of inhabitants, as well as swimming pools, barber shops, nail salons, medium-sized supermarkets, and internet cafes. You can find anything you need in the building, so technically you don’t even need to go outside.

Designed by Alicia Loo, the chief designer of the world’s second seven-star hotel, the Singapore Sands Hotel, the Regent International building was inaugurated in 2013, and quickly became one of the most popular edifices in Hangzhou. The majority of its residents are young professionals who recently graduated college or are about to graduate, but you can also find young influencers as well as small businesses.

According to an article by Chinese news agency Sina, smaller apartments without windows usually rent for around 1,500 RMB ($220) per month, while larger units with balconies can rent for up to 4,000 RMB (550 USD) per month or more. Judging by the bustling atmosphere, Regent International has plenty of tenants.

Offering more than 260,000 square meters of space, the Regent International apartment building in Hangzhou is one of the largest of its kind in China. The number of inhabitants has been a matter of debate on Chinese social media, but judging by the number of rooms and the number of floors, it is estimated that between 11,000 and 22,000 people live in the building at any given time.

Photos and videos of the Regent International started going viral on Western social media last month, with some posts racking up millions of views. Most people are blown away by the number of inhabitants, with some declaring that they grew up in towns with fewer people than what the colossal building can accommodate.