Sancaktar Hayrettin Mosque

Sancaktar Hayrettin Mosque (Sancaktar Hayrettin Câmîi, also Sancaktar Hayrettin Mescidi, where Mescit is the Turkish word for a small mosque, or Sancaktar Mescidi) is part of a former Eastern Orthodox monastery converted into a mosque by the Ottomans. It is generally believed that the small building belonged to the Byzantine Monastery of Gastria (ῆ ῶ, Monē tōn Gastríōn, meaning "Monastery of the Vases"). The edifice is a minor example of Palaiologan architecture in Constantinople, and is important for historical reasons.

Mosque data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).