The Fountain of Youth at North Park (Allegheny County, PA) is a somewhat hidden feature on the West side of the park. There is no sign or parking lot, but it is pretty easy to get to once you know where it is. While there no longer is a water pump inside (due to being deemed insufficient for human consumption), it is still a neat place to check out. Here is an old newspaper article talking about its closure: https://goo.gl/kfNchQ
McConnells Mill in the Fall, as seen from below the covered bridge. While low water levels made for poor waterfall conditions here, it allowed for a lot more exploration such as this.
This section of Grindstone Run at McConnells Mill State Park is just a couple minutes downstream from Grindstone Falls.
