Balaban Aga Mosque
Balabanağa, Turkey
Balaban Aga Mosque (full name in Balaban Ağa Mescidi, where mescit is the Turkish word for a small mosque) was a mosque in Istanbul, Turkey, converted from a former Byzantine building. Its usage during the Byzantine era is unclear. The small edifice - pulled down in 1930 to open a new road - was a minor example of architecture of the Byzantine early period in Constantinople.
Mosque data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).