Field of Mars?

Photo I took from, (I think) the second level of the Eiffel Tower. Why is it called the Field of Mars (Champs de Mars)? Because, as you look away from the tower, down that long strip of green that looks like a golf club airstrip, what appears at the top of this photo: the Military School, built by Napoleon! Get it? Mars -- the god of war and the military school! Much of Paris is planned this way.