NOTE: THE PEOPLE OF AL'ULA and MADA'IN SALAH HAVE VERY RESPECTFULLY ASKED THAT NO PERMANENT INVASIVE ANCHORS OR ALTERATIONS OF THE ROCK BE USED THERE. NO BOLTING, NO CHIPPING, ETC. Umm Ad Darj is a huge monolithic sandstone mountain, covered with ancient inscriptions, petroglyphs & graphs, carved stairways, cisterns, etc., much of it two to three thousand years old. The archeological bounty here is incredible. Please stay off of anything that looks even remotely like a relic. Access is not controlled here, but it should be. It's amazing. If you're not a hardcore climber and you only do one climb in Arabia, this should be it. If you're interested in doing Umm Ad Darj, contact firstname.lastname@example.org. I'm not giving his address to plug his business, I'm giving it because he is THE expert on the area, he has a good sense of adventure, and he takes great pains to see that the archeology remains intact and unaffected.
Umm Ad Darj means "The Mother of Stairs". From the summit it's easy to see why it has the name.
Umm Ad Darj is located in AL 'ula, a kilometer NW of the checkpoint on Ring Road, and SW of the junction of Ring and Ha'il Roads.
Don't miss the Nabatean ruins while you're in this area. In fact, Al'ula/Mada'in Salah is the best of what should be the classic adventurer's trilogy: Wadi Rum-Petra-Al'ula