Petra (Arabic: ٱلْبَتْراء, romanized: Al-Batrāʾ; Greek: Πέτρα, "Rock"), originally known to its inhabitants as Raqmu (Nabataean: 𐢛𐢚𐢒 or 𐢛𐢚𐢓𐢈, *Raqēmō), is a historic and archaeological city in southern Jordan. Famous for its rock-cut architecture and water conduit system, Petra is also called the "Rose City" because of the colour of the sandstone from which it is carved. The city is one of the New 7 Wonders of the World and a UNESCO World Heritage Site.
The area around Petra has been inhabited from as early as 7000 BC, and was settled by the Nabataeans, a nomadic Arab people, in the 4th century BC. Petra would later become the capital city of the Nabataean Kingdom in the second century BC. The Nabataeans invested in Petra's proximity to the incense trade routes by establishing it as a major regional trading hub, which gained them considerable revenue. Unlike their enemies, the Nabataeans were accustomed to living in the barren deserts and thus were able to defend their kingdom. They were particularly skillful in agriculture, stone carving, and rainwater harvesting.
Petra flourished in the 1st century AD, when its Al-Khazneh structure, possibly the mausoleum of Nabataean king Aretas IV, was constructed, and its population peaked at an estimated 20,000 inhabitants. Nabataea fell to the Romans in 106 AD, who annexed and renamed it as Arabia Petraea. Petra's importance declined as sea trade routes emerged, and after an earthquake in 363 destroyed many structures. In the Byzantine era, several Christian churches were built, but the city continued to decline and, by the early Islamic era, it was abandoned except for a handful of nomads.