I read about this place a few days ago while I was looking for interesting places to go outside Riyadh. The photos looked cool and I conceived my husband to drive me out, but I had no idea it would be so wonderful. The things I'd read talked about bouldering and rock climbing and didn't really focus on the fact that this is a little slot canyon.
It's a little more than an hour south of Riyadh from the edge of the city. There are several different routes and my favorite is along 5399 rather than 509 or out toward Al Kharj. After that, the new road toward Howtat Bani Hamim is quick and easy. The slot canyon part of the wadi is about half a kilometer long and maybe 30 feet deep at the most.