I'm sorry Martin, but how does a building (I'm assuming you are talking about the one that has the Eiffel Tower on it) is 40 feet tall and the Gondolas are 25 feet in the air. That building is still 15 feet above and the solution, if it doesn't already exist is to put a short wall around the top of the building that will hide the bottom of the tower and it will have forced perspective just like it does now from the other direction.
Unless you are talking about a different tower, I am talking about the Eiffel Tower. Not sure which tower you are talking about otherwise. If we are talking about the same one, then it seems to me to be not much of a problem. It may require just a little more suspension of disbelief then usual, but, that's up to us to provide.