Champ-de-Mars, 7e. Strangely enough this classic Paris landmark did not receive official recognition as a national monument until 1964. Gustave Eiffel ‘s 300 m-tall iron cat’s cradle of a tower was the tallest building in the world when it was completed in time for the World Exhibition in 1889. Commissioned to commemorate the centenary of the Revolution, the design was universally slated at the time and considered an affront to French art and history. Today it is one of the most popular sights in the capital. Long queues form in summer, but on a clear day the views stretching 70 km in each direction are worth the wait.