Derinkuyu

Nothing above ground prepares you for Derinkuyu. You walk into what looks like a modest ticket office next to an ordinary Cappadocian village, descend a set of stairs, and keep descending — eighteen levels, sixty metres down at the deepest point I was allowed to reach, through tunnels so narrow in places that I had to turn sideways and duck simultaneously, my backpack scraping both walls. It was carved out of soft volcanic tuff starting perhaps as early as the eighth century BC by Phrygians, expanded massively by Byzantine Christians hiding from Arab raids, and used as recently as the twentieth century by locals sheltering from various threats. At its peak it may have held twenty thousand people, plus their livestock, for weeks at a stretch.

What gets you isn’t just the scale, it’s the design intelligence. There are ventilation shafts, over fifty of them, that still moved air past me at the bottom level despite the crush of tourists above. There are wells dug deep enough that surface poisoning couldn’t contaminate them, stone doors shaped like giant millstones — some over a metre across, weighing as much as a car — that could be rolled shut from the inside and were far too heavy for anyone attacking from outside to move. There’s a room believed to be a school with two parallel long benches carved from the rock, a winery with grape-press channels still visible in the floor, a chapel with a cruciform floor plan, stables with feeding troughs at knee height. It’s a fully realized underground civilization built to survive sieges lasting months, not days.

I went with a guide who’d grown up in the region, and at one point, standing in a chamber with six tunnel openings branching off it, she told me that the connecting tunnel system between Derinkuyu and nearby Kaymaklı — roughly nine kilometres — has never been fully mapped, and that new sections still get discovered periodically when a farmer’s tractor sinks unexpectedly into a hollow. I believed her instantly, standing in a hole that already felt older and stranger than anything I’d have guessed from the parking lot above.

When to go: Any season works since you’re underground regardless, but arrive early morning to beat tour buses — the tunnels are genuinely narrow and a crowd turns the experience into a queue. Not recommended if you’re claustrophobic; some passages require crouching for stretches.