Because we were in Paris in October, the lines for the elevator to the top floor were quite manageable. This is a phenomenal engineering feat to behold, especially on the elevator trip up to the top.
Go to the Eiffel Tower near sunset; when you come down from the top, the entire building will be lit up and that's a wonderful bonus to your visit.
Going to the top of the Eiffel Tower is an absolute must-do activity when you visit Paris. But bring your patience if you travel there in the spring or summer. I've been told that the line for the elevator can result in two hours or more of waiting time. Well worth it, though.
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