The Eski Imaret Mosque is a former Byzantine church converted into a mosque by the Ottomans. The church has traditionally been identified as belonging to the Monastery of Christ Pantepoptes, meaning "Christ the all-seeing". It is the only documented 11th-century church in Istanbul which survives intact, and represents a key monument of middle Byzantine architecture. Despite that, it remains among the least studied buildings in the city.

Zeyrek is a neighbourhood in the municipality and district of Fatih, Istanbul Province, Turkey. Its population is 12,863 (2022). It is a picturesque but poor neighbourhood. It takes its name from the huge and prominent Zeyrek Mosque which started life as a Byzantine church and sits on a plateau, overlooking the Golden Horn.