875 NORTH MICHIGAN AVENUE, CHICAGO, 343 metres: Formally the John Hancock Building, back in 1968 this was the second tallest building in the world. A major tourist attraction with an open air sky deck and a 95th floor restaurant, it will lose its American top ten place with the opening of Chicago’s 365m Vista Tower later this year, incidentally the world's tallest building designed by a woman, Jeanne Gang

Megaprojects: 10 tallest buildings in North America – in pictures