Visiting Paris is 3rd week in May, 2014 with my sister. Checked a month ago and plenty tickets were available. Looked this morning and all tickets for May 2014 are booked except for 2 single tickets at separate times Very curious, tickets for April and June still available. Anyone have any idea why May would be all booked? This is my first and only time in Paris, and would hate to miss out on going up in this iconic landmark.