2 Best Sights in Cappadocia and Central Turkey, Turkey

Meaning "deep well," Derinkuyu is the deepest of the known underground cities that have been explored. Eight floors are open to the public, though there may be many more. The subterranean labyrinth has stables, wineries, a chapel and baptismal pool, a school, scores of other interconnected rooms, and as many as 600 entrances and air ducts. You'll also see a ventilation shaft that plunges 180 feet from ground level. Claustrophobes, take note: spaces here are so tight that you'll have to walk doubled over for about 330 feet up and down steps in a sloping cave corridor.

About 9 km (6 miles) north of Derinkuyu, Kaymaklı was discovered in 1950 and is thought to be the largest of Cappadocia's underground cities in square area, though fewer levels can be visited than at Derinkuyu. It's believed that many of the current homes in the area are connected to the tunnels, and the story goes that before parts of the underground city were closed off to the public, unsuspecting homeowners periodically found tourists popping up in their living rooms. The city extends below ground for eight levels, of which only four are currently open. Sloping corridors and steps connect the floors, with different areas used as stables, kitchens, wineries, and a church. The ceilings are low and can be difficult for tall visitors to navigate.