List of tallest buildings  This list of tallest buildings includes skyscrapers with continuously occupiable floors and a height of at least . Non-building structures, such as towers, are not included in this list (see list of tallest buildings and structures). Historically, the world's tallest man-made structure was the ancient tomb - the Great Pyramid of Giza in Egypt, which held the position for over 3,800 years until the construction of Lincoln Cathedral in England in 1311. Until the completion of the Washington Monument in 1884 the world's tallest buildings were Christian churches and cathedrals in Europe. The early skyscraper was pioneered in Chicago with the Home Insurance Building in 1885, forming the basis for which the United States would hold the position of the world's tallest building throughout the 20th century until 1998, when the Petronas Towers were completed. Since then only two buildings have held the title: Taipei 101 in 2004 and Burj Khalifa in 2010. Since the beginning of the 21st century, the Middle East, China, and Southeast Asia have experienced booms in skyscraper construction. 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 . However, the CTBUH only recognizes buildings that are complete, and some buildings included within the lists in this article are not considered finished by the CTBUH. In 1996, as a response to the dispute as to whether the Petronas Towers or the Sears Tower was taller, the council listed and ranked buildings in four categories:  Spires are considered integral parts of the architectural design of buildings, changes to which would substantially change the appearance and design of the building, whereas antennas may be added or removed without such consequences. The Petronas Towers, with their spires, are thus ranked higher than the Willis Tower (formerly the Sears Tower) with its antennas, despite the Petronas Towers' lower roofs and lower highest point. Until 1996, the world's tallest building was defined by the height to the top of the tallest architectural element, including spires but not antennae. This led to a rivalry between the Bank of Manhattan Building and the Chrysler Building. The Bank of Manhattan Building (i.e. 40 Wall Street) employed only a short spire and was tall and had a much higher top occupied floor (the second category in the 1996 criteria for tallest building).