An underground city carved beneath Turkey could hide 20,000 people and their livestock

Beneath the town of Derinkuyu in Turkey’s Cappadocia region lies one of the strangest surviving works of ancient engineering: a city dug straight down into the rock, descending through level after level of rooms, corridors and shafts. Rather than building upward with walls and roofs, the people who made it hollowed out a place to live inside the earth itself. At its fullest, historians estimate the warren could shelter thousands of residents together with the animals they depended on, all sealed away from the surface for weeks at a time.

How the soft volcanic rock made it possible

The site owes its existence to geology. Long before anyone tunneled here, eruptions blanketed central Anatolia in thick layers of volcanic ash that hardened into a soft, porous stone often called tuff. That rock is easy to carve with simple hand tools yet firm enough to hold a ceiling once it is exposed to air. Diggers could open a chamber with picks and shovels and trust it not to collapse, then keep going deeper as the family or community grew.

The same material shaped the whole landscape above ground, where wind and water have sculpted the famous cone-shaped pillars and hollowed spires of the region. Residents simply turned that natural workability to their advantage, extending caves into a planned network of living quarters, storage rooms, wells and ventilation passages that reached far below the fields.

A vertical maze built for daily life

What makes the complex remarkable is not just its depth but its completeness. Excavated levels held spaces for sleeping, cooking, worship, food storage and the pressing of grapes and oil, connected by narrow stairways and sloping tunnels. Ventilation shafts ran from the deepest chambers up to the surface, carrying fresh air down and allowing smoke and stale air to escape, so that people and animals could survive for extended stretches without going outside.

Water came from wells sunk into the rock, some of which did not open onto the surface at all, reducing the risk that an enemy could poison the supply from above. Stables kept livestock near the upper levels, where ventilation was easiest, while grain and other provisions filled dedicated storerooms deeper in. The result was less a single shelter than a functioning settlement stacked underground.

Defenses against a dangerous surface

The design reads as a response to danger. Large circular stone doors, cut like millstones, could be rolled across key passages to seal a level from the inside, blocking intruders while defenders retreated further down. Because the stones could only be moved from within, an attacker who forced an entrance still faced choke points at every turn.

Over the centuries the region changed hands repeatedly and faced raids and invasions, and communities that lived through those upheavals had strong reasons to keep a hidden refuge ready. The underground cities of Cappadocia are widely understood as places of retreat during times of conflict, where whole populations could vanish from view and wait out a threat.

Part of a wider underground world

Derinkuyu does not stand alone. Cappadocia contains a network of rock-cut settlements, cave dwellings and subterranean complexes, and the broader area is recognized for its exceptional carved landscape and human-made caverns. The region’s rock sites and their remarkable underground architecture are listed among the world’s protected cultural and natural treasures, a status that reflects both the artistry of the carving and the scale of what was accomplished with hand tools. Documentation of the area’s rock sites and multi-level underground refuges places them among the most significant of their kind anywhere.

Some passages are believed to have linked separate underground towns, allowing people to move between them without surfacing. That degree of connection hints at long-term planning across generations, not a single burst of digging in a crisis.

Generations of hands at work

The complex was not carved in a single lifetime. Its earliest chambers were likely opened long ago and then extended and deepened by successive communities that inherited the site and adapted it to their own needs. Each generation could dig further, add rooms and refine the systems that made underground life bearable, so the finished maze represents the accumulated labor of many people across a very long span.

That layered history helps explain the site’s complexity. Features such as the ventilation shafts and defensive doors were not necessarily part of one grand plan but solutions added and improved as circumstances demanded. Different religious and cultural groups are thought to have occupied the region over time, and the underground spaces reflect that continuity of use, serving as shelter and sanctuary through repeated shifts in who controlled the surface above.

The practical knowledge required to keep such a place habitable, from managing airflow to maintaining water sources, would also have passed down through the community. Living underground for any length of time was a skill as much as a structure, and the survival of the complex speaks to how effectively that knowledge was preserved and handed on.

Why it still draws visitors and researchers

Today parts of the complex are open to the public, and walking down through its levels remains a disorienting experience: the air cools, the light fades, and the sheer labor represented by every chamber becomes obvious. Archaeologists continue to study how the ventilation, water systems and defensive features worked together, and how many people the deepest sections could realistically hold.

The enduring appeal is partly the mystery of scale. A community that could feed, water and hide a large population underground, keep its animals alive and defend its passages had solved a genuinely hard problem with modest means. The carved city stands as evidence of how far people would go, quite literally, to stay safe.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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