The Petronas Twin Towers is the tallest building in the world at a height of 451.9m (1483 feet). The twin towers is connected at the 41st and 42nd floors via a sky bridge measuring 58.4 meters. The towers were designed by Cesar Pelli and Associates, and costed US$1.2bn. The towers were built as the corporate headquarters of PETRONAS and as part of the Kuala Lumpur City Centre (KLCC) project. The 88-floor tower was designed with geometric principles which is at the core of Islamic architecture. Geometric symbols used represented Islamic principles – stability, harmony, unity and rationality.