The Regent International Center is an apartment building located in Qianjiang Century City, Hangzhou, China. It is the largest apartment building by capacity in the world; capable of housing up to 20-30,000 persons. It has been called a "vertical city", as it has many amenities contained within the building, and residents would theoretically never need to leave the building. A large amount of the building's population is students and recent migrants to the city as a temporary residence.