Possibly US64 between Franklin and Highlands, NC.
Bridal Veil Falls is on the road right-of-way and the road used to go under it. Dry Falls requires that you park and walk a couple hundred yards to the falls. You can walk behind the falls but you will not stay dry.
Pay attention to signs about maximum vehicle length. That section of 64 is winding, narrow and has a narrow shoulder with a rock wall on one side and a hundred foot drop on the other.
The highway scenes in the movie Thunder Road were filmed there. There is a small National Forest campground (Cliffside) along the road. Not sure when it will open this spring, I think it had to close early last fall due to fires in the area.