This is a roadside stop near Damascus, Virginia with a neat rock tunnel constructed in 1901 known as the "shortest tunnel in the world" and a 45 foot waterfall.
First, from the parking lot, there is a trail which climbs up to walk on top of the rock. The top of the rock is narrow, but has hand rails to hold on to.
Once finished walking on top of the rock, cross the road (be extremely careful) and walk away from the tunnel. Here is a good angle to take a photo of the tunnel which was created in 1901.
Still walking away from the tunnel, there will be a well-marked trail that breaks off to your left. This is a very short loop trail leading to the 45' Backbone Falls. The loop trail will lead back to the road, and you will simply have to carefully cross the road again to return to your car.