List of tallest buildings
The international non-profit organization Council on Tall Buildings and Urban Habitat (CTBUH) was formed in 1969 and announces the title of "The World's Tallest Building" and sets the standards by which buildings are measured. It maintains a list of the 100 tallest completed buildings in the world. The organization currently ranks Burj Khalifa in Dubai as the tallest at . The CTBUH only recognizes buildings that are complete however, and some buildings included within the lists in this article are not considered finished by the CTBUH.
List of tallest buildings and structures
Before Burj Khalifa was completed, Willis Tower led in the height-to-tip category with after its antenna was extended in 2000, making Willis Tower slightly taller height-to-tip than the WTC north tower's antenna that measured . After the September 11, 2001, attacks, the WTC became the world's tallest two buildings to be destroyed or demolished. They took that distinction from the Singer Building, which stood tall until the late 1960s where One Liberty Plaza now stands right across Church Street from the WTC site.