Highest load-bearing walls

The 417 m (1,368 ft) high walls of the destroyed 1 World Trade Centre building in New York City, USA, were the world's highest load-bearing walls. The vast majority of the world's high-rise buildings use a concrete-and-steel framework on which the outer walls simply 'hang'. However, the design of the Twin Towers meant that the strong steel outer walls formed a stiff rectangular 'box' upon which carried the full weight of the building.