The Flatiron, New York City, New York, USA

It’s not the tallest building in New York City, nor is it the most famous, but the Flatiron building in Manhattan is definitely among the city's most striking. A triangular, 22-storey office block that looks almost two-dimensional when viewed from the side, the building was constructed in the Beaux-Arts style and measures just six feet (2m) across at its narrower end.