List of tallest buildings and structures
The tallest artificial structure is Burj Khalifa, a skyscraper in Dubai that reached in height on January 17, 2009. By April 7, 2008 it had been built higher than the KVLY-TV mast in North Dakota, USA. That September it officially surpassed Poland's Warsaw radio mast, which stood from 1974 to 1991, to become the tallest structure ever built. Guyed lattice towers such as these masts had held the world height record since 1954.
One World Trade Center
On November 12, 2013, the Height Committee of the Chicago-based Council on Tall Buildings and Urban Habitat (CTBUH) made the controversial announcement that One World Trade Center was the tallest building in the United States at , declaring that the mast on top of the building is a spire since it is a permanent part of the building's architecture. By the same reasoning, the building was also the tallest in the Western Hemisphere.