Mada’in Saleh is one of Saudi Arabia’s two UNESCO World Heritage Sites. The city was settled by the Nabataeans, whose capital was Petra in Jordan, in the first century B.C., and most of the 131 rock-cut tombs date to the first century A.D.

I don't want to overdo it with too many of these full tomb views, but I liked this image as it's clear how the entire tomb is cut into the rock.

Some of the details on a tomb: