The Derinkuyu Underground City is one of the largest ancient underground settlements ever found. Carved into the soft volcanic tuff of Cappadocia, it descends at least eight floors to a depth of around 85 metres and contains living quarters, stables, food storage rooms, wineries, oil and wine presses, a school, and churches — a fully self-contained world beneath the earth.
The complex is thought to have been expanded by early Christians seeking protection from successive waves of invaders, though the deepest levels may predate the Byzantine period. Ventilation shafts run the full depth of the city, and wells were designed so that water from the upper levels could not be poisoned to reach the floors below. The engineering is meticulous: corridors narrow at strategic points, forcing would-be attackers to enter in single file where defenders had the advantage. It was discovered by modern authorities in 1963 and has been open to the public since 1969. The accessible portions are genuinely claustrophobic, especially the lower levels; visitors who dislike confined spaces should be prepared.