Umm al-Biyara, the highest mountain in Petra, southern Jordan, was the first Iron Age Edomite site to be extensively excavated. It was a domestic, unwalled settlement of stone-built longhouses dating to the 7th-6th centuries BCE. The stratigraphy, pottery, small finds and inscribed material, including the important bulla of Qos-Gabr, King of Edom, are described here in detail. This information is supplemented by chapters on the use of space and a landscape study of mountain-top sites in the Petra region. The later remains on the edge of the summit indicate a major Nabataean complex of buildings, possibly a palace, which would make this the first Nabataean palace in Petra to be explicitly identified.