Petra is a city along a gorge, the dwellings are actually caves; Petra in Latin means rock.
It has a fascinating history.
Wikipedia explains it well
There is a plaza somewhere in the middle of the gorge, where I could buy batteries for my camera!! …Otherwise you would not see my pictures.
The Romans used the city to collect taxes from caravans passing through the gorge, and they had official buildings… well, still a cave, but Roman-like façade.
At the end of the gorge there is an amphitheatre built by the Romans. We missed by few days a show here, a tribute to Pavarotti.
Note: there are still some people living around, but if you want to take a picture of a passing lady, you need to pay, and I had only a credit card with me; do not do that mistake if you plan to visit, the local girl I missed to catch on camera was gorgeous.