http://www.paris-travel-guide.info/eiffel-tower-descriptions/
eiffel tower questions?
what is the physical description of the Eiffel tower?,
How is the Eiffel tower used today?, why was the Eiffel tower constructed?
Their are many “truths” on why the eiffel tower was built. The official one is for the 1889 world expo in Paris where Gustav Eiffel started building the tower in 1887 (note he started to built it horizontally then pulled it up straight)
The real reason is obvious when you know Gustav Eiffel owned a metalworks company, On September 18 1884 Eiffel registered a patent “for a new configuration allowing the construction of metal supports and pylons capable of exceeding a height of 300 metres”, equivalent to the symbolic figure of 1000 feet. The world expo was his marketing ploy. The tower was to be later taken apart but its sucess saved it.
On a side not Eiffel also build the twin edifices of the Porto viaduct and the Garabit viaduct in the Cantal region of France, and his company designed the structure of the statue of liberty. He also worked on the locks of the Panama canal, his biggest contract, which was badly managed by Ferdinand De Lesseps and was one of the biggest financial scandals of the time.
I could give you my theory on what it is used for today, except for a pointy christmas tree, some would tell you it represents french male ego…
I also could copy paste you details of the structure (phisical discription) but I rather give you a link to the most complete information site on the eiffel tower (in english ty)
One little note, the top of the tower moves with the winds. Inside the tower you can actually see how much it moves. The view of Paris is fabulous. It is indeed a pretty city. I was on the london eye and london does not have the same charm paris has. Sorry brits 
Hope that helped
Suicide attempt (read description) from Eiffel Tower