Notre-Dame de Paris

A Gothic cathedral in the middle of Paris, on the Île de la Cité, begun in 1163 under Bishop Maurice de Sully and essentially finished around 1345. At 130 metres long, with two 69-metre towers, it was one of the first cathedrals to use free-standing flying buttresses on a large scale, which let the walls thin out and the rose windows open up. It was badly damaged during the Revolution and heavily restored by Viollet-le-Duc in the 19th century, who added the spire and plenty of details that now pass for original.