On the west side of Atatürk Boulevard, the Zeyrek Cistern—also known as the Pantokrator or Unkapanı Cistern—is partially visible above ground. This cistern was part of the Byzantine Pantokrator Monastery complex, now the Zeyrek Mosque, built against the hillside. Because of its hillside location, one of its outer walls is visible, reinforced with buttresses and niches.

The reconstructed Hadrianic water line runs along the hillside near the cistern’s southwest corner, which has been confirmed as an inflow point, making the Hadrian Waterway its likely source. Water entered the cistern through an elevated channel that encircled the main chamber at gallery level, probably connecting on the southwest side.

The cistern is also referenced as E5/2 in archaeological records (Crow et al., 2008, p. 148).