I know a few "usual suspects" in Fethiye apparently offer to give a guided tour of the rock tombs (which is not necessary and also they probably know no more than you do about them
) - but on more than one occasion I have heard that people were offered an exciting opportunity to visit a rock tomb that can't be seen from the road - I assume it is over the brow of the cliff (do cliffs have brows?).
Apparently unless your cliff climbing skills are up to scratch you are going to need to follow your "guide" to a secret path that follows a slighly less vertical route.
Now I know these guys are basically conmen. But does anyone know if there actually is a tomb (or anything else of interest) up there?