Hagia Sophia, İznik
İznik, Turkey · built 600
Hagia Sophia mosque (lit. 'the Holy Wisdom', Ancient Ἁ, Hagía Sophía, Ayasofya) in İznik (Nicaea) in Bursa Province, Turkey, was built as a Byzantine-era basilican church. Converted into the Orhan Mosque (Orhan Camii) after the Ottoman conquest, it was turned into a museum in 1935. The church is now once again in service as a mosque. It is in the town centre of İznik, within the old walled area.
Church data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).