Petra. Blue columns.

Petra boasts an amazing number of churches. Many old tombs were turned into churches or cathedrals, and many tombs later had crosses inscribed into their walls. Along with this, there are three churches built almost side by side. The Christian era at Petra came during the 3rd and 4th centuries, when many of the Nabataean people had emigrated elsewhere.
Located just above the main church is the blue church, named after it's impressive Blue columns.