On the edge of the Arabian Desert, Petra was the glittering capital of the Nabataean empire of King Aretas IV (9 B.C. to 40 A.D.). Masters of water technology, the Nabataeans provided their city with great tunnel constructions and water chambers. A theater, modelled on Greek-Roman prototypes, had space for an audience of 4,000. Today, the Palace Tombs of Petra, with the 42-meter-high Hellenistic temple facade on the El-Deir Monastery, are impressive examples of Middle Eastern culture.