The Eiffel Tower was created as a centrepiece for the 1889 Exposition Universelle, a World's Fair which celebrated the centennial of the French Revolution. The engineer Gustave Eiffel, had a permit for the tower to stand for only 20 years. It was to be dismantled in 1909, when its ownership would revert to the City of Paris. The City had planned to tear it down (part of the original contest rules for designing a tower was that it could be easily demolished) but as the tower proved valuable for communication purposes, it was allowed to remain after the permit expired. Today it is the most-visited paid monument in the world. (Wikipedia)
The observatory at the very top remains closed as a result of the fire of August 2000. The second level deck (in the center) is 600 steps above ground level, which I climbed everyone of them. About halfway up, I realized I still had my camera backpack on, wishing I had left it on the ground with someone. It seemed to weigh more every step I took. It is an awesome structure and must be seen up close and inside to really appreciate. It's hard to believe it was built, just to be torn down later.
If you look just beyond the base of the tower, you can see another building in the far distance. This is the Montparnasse Tower, a modern office building. It has a great view of the Eiffel Tower too.