This is an awesome historical site-seeing mode of transportation. Fantastic views of the river and the downtown! Also it's pretty inexpensive, and fast! It runs late, too, so you can enjoy the night life.
When you get to the top, there is a lot of great historical information to look at with pictures, artifacts and more. There is also a gift shop, though it closes before the incline itself does. It's a short walk over to a scenic outlook with a statue of George Washington
The fact that the windows can be opened a bit to let the breeze in was really nice.