One of the more fascinating aspects of Tolkien's imaginary geography is the immense underground complex of caverns and dwarf-carven halls and chambers he devised for Khazad-dum. Until recently, I never really gave the possible inspirations for Tolkien's dwarf-cities much thought.

Dwarf-cities go all the way back to Tolkien's first mythology, The Book of Lost Tales. Other underground cities held Tolkien's fascination, too. As a British soldier assigned to the front lines in the First World War, he would have lived in underground cities -- bunkers and shelters dug into the ground and connected by trenches.

Those accomodations were, by all accounts, anything but warm and cozy. Succumbing to Trench Fever, Tolkien was returned to England and while in the hospital he began writing the stories that would eventually comprise his incomplete "mythology for England".

By this time in his life, Tolkien may also have learned something about the underground cities of Cappadocia. The earliest such fortresses were built by the Hittites, whose language was the earliest recorded Indo-European language. Tolkien often referred to and drew upon Proto-Indo-European, the reconstructed language that linguists believe was spoken by our Caucausus-based ancestors.

Cappadocia, located in what is now eastern Turkey, was the birth place of St. George, a 3rd century saint who joined the Roman Army and was assigned to serve in Brittannia (England). George reportedly slew a dragon (in Libya, of all places) by striking it under the wing, where its flesh was unprotected by scales.

One of the interesting things about Cappadocia, in my opinion, is that the name is derived from a Persian word meaning "land of beautiful horses". I think that name would have some appeal to Tolkien. He may have been familiar with the name and its history from the writings of Xenophon, Herodotus, and Strabo. But Tolkien would also have encountered it in Medieval literature as the Crusaders brought the legend of St. George and the Dragon back to western Europe.

I think it unlikely that Tolkien could have known much about Cappadocia's underground cities (if he knew about them at all) while writing The Lord of the Rings, but they were supposedly mentioned in at least one ancient source. In 1963 archaeologists began excavating the cities and at least one of them was capable of holding up to 20,000 people. It extended 8 levels underground and the corridors or stairways were designed to be defended against invaders in a similar fashion to some of Tolkien's descriptions of Moria.

Another possible source of inspiration could be Haware, an ancient Egyptian city where Strabo described a massive labyrinth, part above ground part underground, with several thousand chambers. Tolkien was strongly influenced by ancient Egypt when he developed his Atlantis mythology ("Numenor") and carried it forward into the emerging Middle-earth mythology.

Tolkien Trivia: Did you know that in 1929 J.R.R. Tolkien assisted archaeologist Sir Mortimer Wheeler in a dig at Lydney Park Estate? They Wheeler excavated an ancient Roman temple and Tolkien provided some etymological information.