Derinkuyu is a town and district in Central Anatolia, Turkey. The district overall has a population of just over 20,000. It wouldn't be a particularly remarkable place, except there's something underneath it that attracts some attention. Something about 60 meters beneath the surface.
|Or, in American units of measurement, a little over half a football field underground|
It's another city. Not one that was buried underneath constant construction like you'd find in London or Rome. A city that was designed and built under the surface. That's not entirely unique, but given the fact that it was built in the Eighth Century B.C. and is the largest underground city ever built, it's pretty goddamn spectacular.
The Derinkuyu Underground City could house the entire modern population of the District of Derinkuyu. If it wanted to. It's pretty much over being populated by now and has moved on to be a sort of retro-touristy kind of place. It's something of a hipster in that way. But you wouldn't understand, it's pretty underground.
The city had room for over 20,000 people, as well as grain stores to feed them all and housing for livestock. There were market districts, warehouses, stables, and more carved into the rock under Derinkuyu. There were even heavy stone doors that could block passages in case of invasions.
It was probably built by the Phrygians, but it's been used and even expanded since then by various Persian, Greek, and Turkic cultures as a dwelling place or a refuge. Today, it's a tourist attraction. If you're ever in Central Anatolia (and really, why wouldn't you be?), you can check it out yourself.
Now, I'm not going to say the Phrygians only found the city and it was originally constructed by dwarves fleeing from Durin's Bane in Khazad-dûm...but I'm not going to say that wasn't the case either. Because I like to keep some hope alive.
|The entrance probably looks like this. I hope.|
Either way, it's a massive, sprawling city that is completely invisible if you look at it like any normal person would. And that's pretty damn cool.