https://en.wikipedia.org/w/index.php?ti ... =903010491
Did you know that the Mongols invaded the area in the 15th century? Genghis Khan must have been pretty old by then.
The region became a key Byzantine military district after the advent of Islam and the subsequent Muslim conquest of Syria led to the establishment of a militarized frontier zone (cf kleisoura and thughur) on the border of Cappadocia. This lasted from the mid-7th to the 10th century during the Arab–Byzantine wars, immortalized in Digenis Akritas, the Medieval Greek heroic epic set in this frontier region. During this period Cappadocia became crucial to the empire and produced numerous Byzantine generals, notably the Phokas clan, warlords (see Karbeas of Tephrike), and intrigue, most importantly the Paulician heresy. Because they were living in such a volatile region, the Cappadocian Greeks created elaborate underground cities in the volcanic formations of eastern Cappadocia and would take refuge in them during times of danger. The Cappadocian Greeks hid in these rock-cut underground towns from many raiders over the next millennium, from 9th century Arab invaders to 11th century Turkish conquerors to 15th century Mongols. As late as the 20th century the local Cappadocian Greeks were still using the underground cities as refuges (Greek: καταφύγια) from periodic waves of Ottoman persecution. The most famous of these ancient underground cities are at the Cappadocian Greek villages of Anaku-Inegi (Ανακού) and Malakopi-Melagob (Μαλακοπή). The Greeks were removed from these villages in 1923, and they are now known as Derinkuyu and Kaymakli. These underground cities have chambers extending to depths of over 80 meters.