The Petronas Towers in Kuala Lumpur, Malaysia, were once the world's tallest buildings but have since been unseated in October 2003 by the Taipei 101 building.
Both Petronas Towers are 452 m / 1,483 ft in height, as a result are currently the tallest twin towers in the world. Both towers shared the world's tallest building title from 1996 to 2003.
Joining the towers is a skybridge which is also open to the public and connects the towers together at levels 41 and 42. The skybridge is 58.4 meters long / 192 ft and weighs 750 tons.
The towers were designed by Argentine architect CÚsar Pelli and completed in 1998. The 88-floor towers constructed of largely reinforced concrete with a steel and glass facade were designed to resemble motifs found in Islamic art, a reflection of Malaysia's Muslim heritage.
They were built on the site of Kuala Lumpur's race track. Because of the depth of the bedrock the buildings were built on the world's deepest foundation going down some 120 meters and requiring massive amounts of concrete. In an unusual move, a different construction company was hired for each of the towers, and they were made to compete against each other. Eventually the builders of Tower 2, Samsung Constructions, won the race, despite starting a month behind Tower 1, built by Hazama Corporation, although Tower 2 ran into problems when they discovered the structure was 25 millimeters off from vertical. Due to a lack of steel and the huge cost of importing steel, the towers were constructed on a cheaper radical design of super high strength reinforced concrete. High-strength concrete is a material familiar to Asian contractors and twice as effective as steel in sway reduction. Supported by 23-by-23-metre concrete cores and an outer ring of widely-spaced super columns, the towers showcase a sophisticated structural system that accommodates its slender profile and provides from 1300 to 2000 square metres of column-free office space per floor.
Below the twin towers is Suria KLCC, a popular shopping mall, and Dewan Filharmonik Petronas, the home of the Malaysian Philharmonic Orchestra.