It is in a basin among the mountains that run from the Dead Sea to the Gulf of Aqaba.
Petra is believed to have been settled as early as 9,000 BC. It became the capital city of the Nabataean Kingdom. The Nabataeans were nomadic Arabs who used Petra because it was near the spice trade routes.
The Nabataean Kingdom became a client state of the Roman Empire in the first century BC. iIn 106 AD they lost their independence. Petra's importance declined as sea trade routes developed. Also, the 363 earthquake destroyed many structures.
The Byzantine Era led to the construction of several Christian churches, but the city continued to decline. By the early Islamic era only a handful of nomads lived in Petra. It stayed unknown to the world until it was rediscovered in 1812 by Johann Ludwig Burckhardt.
Petra has been a UNESCO World Heritage Site since 1985. UNESCO has described it as "one of the most precious cultural properties of man's cultural heritage".
Petra is Jordan's most-visited tourist attraction. Tourist numbers peaked at 1 million in 2010.