bottom line....get there early! Even the advance reservation line does not open until 9am. You need to be there before then to be sure that you make it to the top, due to the crowds. When you take the elevator...do not be tempted to stop and take pictures...go all the way to the very top before the crowds swell. The 1st floor is under renovation as of August 2012 so it is much more crowded on 2nd and top floors! Walk south towards Montparnasse (tall skyscraper) afterwards and visit the Invalides, Ecole Militaire and finish at the Montparnasse tower. This is all walking distance and a full day. You can't experience Paris if you are on the subway all the time.
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