At the first bend in the road that leads through Wadi Bani Kharus from the village of Al Awabi, there's a great slab of smooth pale-grey rock on the opposite side of the wadi. On close inspection of the overhang, you'll see some of the ancient petroglyphs dating from around 3000 BCE for which the wadi is noted. Although some have sadly been defaced by vandals, it's possible to make out a clear sequence of figures on horseback and camels.