Skyscraper Building, Petronas Twin Towers, Malaysia

The Petronas Twin Towers in Kuala Lumpur were the world’s tallest buildings before being surpassed in 2004 by Taipei 101. However, the towers are still the tallest twin buildings in the world. The towers feature a sky bridge between the two towers on the 41st and 42nd floors. It is not directly bolted to the main structure, but is instead designed to slide in and out of the towers to prevent it from breaking during high winds. The sky bridge also acts as a safety device, so that in the event of an emergency in one tower, people can evacuate by crossing the sky bridge to the other tower.