The single-lane road to the top of this Blue Ridge mountain is knotted with hairpin curves and sudden cliffs that offer a horrifying look straight down at tiny trees and buildings and highways - that little white string is a highway? - at its foot. One must drive cautiously, as it is not only narrow and curvy, it is also one of the darkest places in Virginia, according to satellite surveys. This inky night is protected from stray headlights by a gate with nine padlocks, linked one into the other.