The Blue Chapel is believed to have been built slightly later, in the mid-5th century, around the same time as the Petra Church. It was named for the four blue Egyptian granite columns that were presumably moved there from a nearby Nabataean monument. Within the chapel lies a base for a bishop’s throne in the apse, a marble pulpit, and marble chancel posts and screens. The chapel could have served as a pilgrimage hostel or a residence for the church.