A seventh-century BC underground city discovered in Derinkuyu, Turkey, was found to contain stables, schools, chapels—even wine and olive presses. It had a 55-meter ventilation shaft, water channels, and eleven floors, many of which have still not been excavated. What’s more, further discoveries of subterranean “cities” in the area have shown that the city at Derinkuyu was actually linked to them via a tunnel system. When threatened, the residents of the city above ground would retreat underground, block off access to the subterranean city with stone “doors” and wait underground until the danger passed.
Photo credit: Martijn Munneke