The Petronas Towers(Twin tower/KL/Malaysia) were the tallest buildings in the world until the Taipei 101 building, as measured to the top of their structural components (spires, but not antennas). Spires are considered integral parts of the architectural design of buildings, to which changes would substantially change the appearance and design of the building, whereas antennas may be added or removed without such consequences. The Petronas Towers remain the tallest twin buildings in the world. (less info)