But I think we are talking of some man made item aren't we? If we are talking of hills and woods and rivers that had a tremendous impact on the outcome of a battle on American soil, I think I could list houndreds. And even if we are talking of locations, which hill are we to choose on the battlefield of Gettysburg?
Little Round Top (would be my first choice), Cemetary Rige (that's where Pickett's charge went), Cemetary Hill (fierce fighting in the evening of the second day), Culps Hill (fierce fighting on the second and skirmishes on the third day), Oak Hill (a considerable part of Rode's confederate division was slaughtered there on the first day), Bloecher's knoll (that's where the 11th federal corps was outflanked the first day).
If we are talking about parts of the landscape the list is really, really long.