Mini Sky City

Mini Sky City (小天城) is a 57-story, 204m high building in Changsha, the capital of Hunan province in China. It was built in 19 days in 2015 by Broad Sustainable Building, a subsidiary of China's Broad Group, using a modular construction system.^[1][2] The company wanted to use similar techniques to build a much larger project, Sky City, which was intended to be 202 stories tall, but was never built.^[3] In 2017 mini Sky City was involved in international architectural competition SkyCity Challenge, where architects from around the world designed 17 of the hollow atriums located inside of the skyscraper.