Petra was the impressive capital of the Nabataean kingdom from around the 6th century BC. The kingdom was absorbed into the Roman Empire in AD 106 and the Romans continued to expand the city. An important center for trade and commerce, Petra continued to flourish until a catastrophic earthquake destroyed buildings and crippled vital water management systems around AD 663. After Saladin's conquest of the Middle East in 1189, Petra was abandoned and the memory of it was lost to the West.
The first real excavations of the site were in 1929 after the forming of Trans-Jordan. Since that time, Petra has become by far Jordan's largest tourist attraction, partially due to the exposure by the Steven Spielberg movie, Indiana Jones and the Last Crusade, in 1989. Due to the fantastic engineering accomplishments and well-preserved dimension of Petra, the archaeological site was chosen in July 2007 as one of the New Seven Wonders of the World.
The entrance to Petra is a long, winding sandstone canyon known as the Siq (about 2km). There are minor carvings spotted here and there throughout the Siq, but the most impressive sights are the colorful and unusual sandstone patterns in the rock walls. There are also remains of terracotta pipes built into the sides of the canyon that were used in Roman times to carry water.
The High Place of Sacrifice - The site at the top of the mountain contains elaborate rock altars used for sacrifices. From the High Place, one can view much of Petra from above. Beautiful scenery. It can get cold and windy up there. The trek down the back side of the mountain reveals many interesting tombs and carvings that might be missed by the average tourist. The round trip generally takes 1.5-2.5 hours. Not many people go through the back route as it's not always clear where it starts - ask.
The Monastary of Petra - Petra Monastry