ククルボスタン公園

The Cistern of Mocius (Greek: κινστέρνη τοῦ Μωκίου), known in Turkish as Altımermer Çukurbostanı ("sunken garden of Altımermer"), was the largest Byzantine open-sky water reservoir built in the city of Constantinople.

Altımermer (originally Exi Mármara) is a quarter located in the European part of Istanbul, Turkey. It is located in the western part of the district of Fatih (the walled city). Although it is difficult to define exactly its boundary, Altımermer lies between the neighborhoods (mahalleler) of Kocamustafapaşa and Seyyid Ömer.