One of the quietest and most solemn National Park sites I have been to was the Flight 93 National Memorial in SouthWestern Pennsylvania. Here was a huge new building that had artifacts of the crash site and movies and newsreels of the horrific day of September 11, 2001. From the building you can stand on the overlook to the meadows below and see the stone path that shows the exact path the low flying plane took as it crashed into the ground near the hill here. This is a view of the main building way up on the hill from the memorial wall below near the crash site where they list all the names of victims killed in the crash.