Derinkuyu underground city

Derinkuyu goes down about 85 metres on multiple levels and could shelter as many as 20,000 people along with their livestock and food stores. It is the largest excavated underground city in Turkey, one of a number of such complexes across Cappadocia, and it was built for one purpose: to disappear into.

The name means deep well, after the shafts that supplied water both to the city below and the town above. Cappadocian Greek speakers knew it as Malakopia, a name plausibly from the Greek malakos, soft, referring to how easily the local rock works.

That rock is tuff, compacted volcanic ash, and it is the whole reason the place exists. Tuff is soft enough to carve with hand tools and firm enough to hold a ceiling, so an entire settlement could be cut into it. What went in was not a cellar but a working town: wine and oil presses, stables, cellars, storage rooms, refectories and chapels, with kitchens fitted with tandoor ovens of a kind still in use in the region.

The defensive design is the striking part. It could be sealed from the inside with great rolling stone doors, and each floor could be closed off separately, so an intruder who forced one level still faced another barrier below. The deep shafts that give the place its name supplied water to the settlement below and the town above it.

Visitors walk a marked route through part of the complex. The passages are narrow and low, and the descent is steep.