Burj Khalifa in the UAE is the tallest man-made structure in the world.It opened on January 9, 2010.It is also the tallest self-supporting building in the world, formerly known as Burj Dubai, and was initially built of steel and concrete. Designed by Chicago's Owings Architect, Skidmore and Merrill LLP, which designed the World Trade Center, and the Tower of Wales, the government's goal was to promote tourism and diversify the economy, as its economy relies on the oil industry. The tower is about 30,000 dwellings, a 30-acre lake, and a courtyard 7 acres cars, 9 hotels, shopping center and 19 residential towers.