The tallest tower in the world, the long-awaited Burj Dubai, renamed Burj Khalifa to acknowledge a financial bailout by neighboring Abu Dhabi, officially opened on Jan. 4, 2010.
The 200-story Burj Khalifa cost $1.5 billion to build. While mainly residential, the building will have 37 floors of office and retail space.
Burj Khalifa has a height of 828 meters (2,717 feet). Designed by Chicago-based Skidmore, Owings and Merrill LLP, the structure overtook Taipei 101 as the world's tallest in February.
The first skyscraper was erected in Chicago because of the high cost of land and the shortage of space that made “building up” more practical than “building out.” A skyscraper indicates not only size but the way a building is constructed. Most buildings are held up by walls but a skyscraper is held up by a steel skeleton and the walls are not needed to support the building. The walls, often referred to as "curtain walls", can be made of material as light as glass.
Click on the heading above to see a comparison of the 10 tallest buildings in the world.