The Wadi Musa bisects the basin-shaped site of Petra from east to west. Parallel to it is the most important traffic artery of the town, the Colonnaded Street, lined with public buildings. To the south is a rocky spur with its highest point, known as ez-Zantur, located to the southeast above the Great Temple, halfway between el-Habis and the theater. The surface finds conducted in the area of ez-Zantur suggested that there was no fortification wall on this slope, as had long been supposed. Instead a richly furnished residential mansion about 1100 square meters, which covered the central and southern part of the site was found. Erected in the first century CE, this two-story mansion towered above the surrounding buildings and offered its inhabitants spectacular views of the southern landscape of Petra.
No residential area has ever been excavated at Petra and so the Swiss excavations, which were conducted between 1988 and 1997 in two areas on ez-Zantur, known as EZ I and EZ III, have provided dramatic insights into the domestic architecture and way of life of the Nabataean urban middle class between the late first century BC and fifth century CE. The excavation of the mansion, an upper-class residence on the terraced site of EZ IV, begann in 1996 with the goal of expanding the knowledge of Petraean buildings in the ez-Zantur residential district. These excavations were completed in the autumn of 2001.
The results of the excavation seasons 1988–1995 (sites ez Zantur I and ez Zantur III) have been published in four extensive volumes: