“The diwan (meeting room), carved into a hillside to shield it from the wind, is one of the few extant examples of non-funerary architecture in Mada’in Saleh. … [The area was probably used by the Nabataeans] as a cult site. Opposite the hollowed-out room are niches cut into the rock where Nabataean deities were carved – now sadly weathered.” (from Lonely Planet, “Oman, UAE & Arabian Peninsula”)
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.