At the top of Mt. Washington are the best views of all of Downtown Pittsburgh, which is a beautiful City. You can park at the bottom and take the Incline up (that is very cool) or drive to the top (and also take the Incline round trip) and park and walk a bit. The views really are splendid. The three rivers meet (Monongahela, Ohio and Allegheny) and the bridges are beautiful. You can see Three Rivers Stadium from there and the wonderful buildings that make up Downtown Pittsburgh.
There are some lovely homes nearby. There are a few good restaurants in Mount Washington as well.