Pantanassa church
Athens Municipality, Greece · built 901
The Church of the Pantanassa, also known as the Dormition of the Theotokos, is the 10th-century katholikon of a now-vanished monastery in Monastiraki Square, between Athinas and Mitropoleos streets, facing the Monastiraki station, in central Athens, Greece. The church was known as the Great Monastery, and then later as monastiraki ("little monastery"), which eventually became the name of the whole area.
Monastery data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).