'The Monastery'), also spelled el-Deir and ad-Deir/ad-Dayr, is a monumental building carved out of rock in the ancient city of Petra in southern Jordan.

[3] The huge façade, the inner chamber and the other structures next to it or in the wider area around the Deir probably originally served a complex religious purpose, and was possibly repurposed as a church in the Byzantine period.

The façade as a whole boasts a Doric entablature (superstructure containing moldings and bands lying above the capitals), but does not have figures in the metope, only simple roundels.

[citation needed] The role of the Deir, which has been probably built in the mid-1st century CE,[2] cannot be assessed with certainty, with hopes that further excavations could offer an answer.

However, the rock-cut chamber has a large central recess, a cella or adyton (innermost sanctuary), accessed by two short staircases, similar to those leading up to the cult podium of the Temple of the Winged Lions, which would be unusual for a tomb, as well as two low benches along the side walls, which suggest that the chamber was built to serve as a biclinium.

[12][13] After the abandonment of Byzantine Petra with its main churches near the city center, a Christian presence in the form of Greek Orthodox hermits and cenobites living in lavra- or coenobium-type communities of among the ruins of the wider ancient metropolis and its necropoles continued all until the late 19th century.

[14] The area around ed-Deir shows a particular density of such communities, who even left an epigraph on the entablature of the monumental facade, observed by Burckhardt in 1812, but which had already disappeared by 1865.

[14] Magister Thetmarus (Thietmar) documented in 1217 that two Greek monks were living near Petra, but their abode was at the church on the summit of Mount Aaron ('Jabal an-Nabi Harûn', lit.

the mountain of the Prophet Aaron, some 5 km SW of Petra), not at ed-Deir[15] (see original Latin text here and its German translation here).