English: Petronas Twin Towers were once the tallest buildings in the world located in Kuala Lumpur, Malaysia. Now the world's tallest twin structures, the 88-storey buildings were designed by Cesar Pelli & Associates with both towers joined at the 41st and 42nd floors (175m above street level) by a 58 metre-long, double-decker Sky Bridge. Built of steel-reinforced concrete columns clad in stainless steel and glass, with a design based on geometric patterns originating in ancient Islam, the 88-floor buildings are connected at levels 41 and 42 by a double-decker pedestrian skybridge, and each tower is surmounted by a 242-ft-high (74-m) pinnacle. At the lower level, the Petronas Towers also include a concert hall that is home to the Malaysian Philharmonic and a business reference library.