A unique rail system that is still in working condition and used as part of the public transportation system! As we were driving around, we couldn't help notice this contraption going up and down through the trees.
its a cash only system, so double check to make sure what the prices are for going up and down, and to have exact change. The address will take you to the bottom base, you can park there for free (when we went, it was free). I'm not going to lie, it was a bit scary getting on to this thing, but once you're in, it is actually pretty neat.
When you arrive at the top, you get nice views of the park and the city of Pittsburgh. They have pictures that show the history of it as well. There is a self guided tour you can also take for less than a dollar, the gift shop can give you change if you don't have coins, i think it was 50 or 75 cents, but just have exact change in case the gift shop won't change anything.