A view of one of the tunnels under the Hagia Sophia in Istanbul, Turkey. The tunnels are credited with keeping Hagia Sophia from falling victim to excess moisture by serving as a natural ventilation system [3000×4038]

A view of one of the tunnels under the Hagia Sophia in Istanbul, Turkey. The tunnels are credited with keeping Hagia Sophia from falling victim to excess moisture by serving as a natural ventilation system [3000×4038]

by Fuckoff555