Landmarks for homing?

I was on the 4th floor of the library at lunch and I could see the see the smoke stacks just up from the break point (3rd drop - pretty sure that's the break point anyway). What a great landmark for them - 6 miles SSE, or so. It is also the 2nd training drop and, I'm pretty sure by their flying, something they look for from the 3rd training drop. I think they use the parkway to navigate too. Some others believe so as well.