The Özkonak Underground City, about ten kilometres north of Avanos, is the least-visited of Cappadocia's major underground complexes. That alone makes it worth choosing over the better-known sites at Derinkuyu or Kaymakli — the tunnels feel less like a theme park and more like what they actually were: a refuge for thousands of people hiding from raids.
The complex descends four levels and includes stables, storage rooms, a winery with large carved vats, living quarters, and ventilation shafts that also served as wells. The blocking doors — massive stone wheels rolled across tunnel entrances — are in position and largely intact. Bring a jacket; the temperature underground stays around 8°C year-round. It is about twenty minutes from Avanos by car or a pleasant bike ride along the valley.