The radical cast-iron tower was built for the 1889 World Fair and the centenary of the 1789 Revolution by engineer Gustave Eiffel. Eiffel made use of new technology that was already popular in iron-framed buildings. Construction took more than two years and used some 18,000 pieces of metal and 2,500,000 rivets.

The 300m (984ft) tower stands on four massive concrete piles; it was the tallest structure in the world until overtaken by New York's Empire State Building in the 1930s. Vintage double-decker lifts ply their way up and down; you can walk as far as the second level.

There are souvenir shops, an exhibition space, café and even a post office on the first and second levels. The smart Jules Verne restaurant, on the second level, has its own lift in the north tower. At the top (third level), there's Eiffel's cosy salon and a viewing platform with panels pointing out what to see.

Views can reach 65km (40 miles) on a good day, although the most fascinating perspectives are of the ironwork itself. At night, for ten minutes on the hour, 20,000 flashbulbs attached to the tower provide a beautiful effect. To avoid the queues, come late at night.