The underground city of Kaymakli | Turkey

Postcard
Göreme National Park and the Rock Sites of Cappadocia is a UNESCO World Heritage site that covers the region between the cities of Nevşehir, Ürgüp and Avanos, the sites of Karain, Karlık, Yeşilöz, Soğanlı and the subterranean cities of Kaymaklı and Derinkuyu.

These cave-cities were excavated as early as Hittite times to protect againt plundering enemies. There are 36 underground cities in Cappadocia and the widest one is Kaymakli underground city.