Basilica Cistern

The Basilica Cistern hides beneath the streets of Istanbul as a vast, subterranean reservoir. Three hundred thirty-six marble columns rise from the shallow water in perfectly aligned rows, supporting a forest of brick arches. Emperor Justinian commissioned this structure in the sixth century to ensure a reliable water supply during a siege. Workers hauled these columns from older temples across the empire. Two of them stand on massive, carved heads of Medusa, placed sideways and upside down to neutralize their legendary, petrifying gaze.