Sacré Coeur Basilica
Built on Montmartre hill, and overlooking the whole city, the Sacré Cœur Basilica is 130m above sea level. Its construction started in June 1875, it was completed in 1914 and consecrated in 1919. In the shape of a Greek cross, adorned with 4 domes, it is one of Paris' most coveted monuments. Its crypt, like its bell (the largest in France), or even the mosaic covering its ceiling (the largest in the world) will amaze you.