Cistern of Aspar

The Cistern of Aspar (Greek: ἡ τοῦ Ἄσπαρος κινστέρνη) or Great Cistern (Greek: μεγίστη κινστέρνη), known in Turkish as Sultan Selim Çukurbostanı ("sunken garden of Sultan Selim"), was a Byzantine open-air water reservoir in the city of Constantinople.