The nation of Turkey probably conjures up images of ancient monuments and beautiful Mediterranean beaches, but there's a completely different world that exists underneath the Turkish region of Cappadocia. There are some 200 cities lying below ground – Derinkuyu and Kaymakli are the best-known – that are believed to have been established in the seventh and eighth centuries B.C. as a place for inhabitants to flee from hostile invaders.
Derinkuyu, for example, had enough room for 20,000 people and their livestock. It was made up of many caves and passages carved into the volcanic rock on multiple levels, some as deep as 200 feet (60 m) underground.
The underground cities were also used in the 14th century by Christians escaping the Mongols, and as recently as the early 20th century, they provided a safe place for those fearing persecution during the Ottoman Empire. According to legend, the cities were forgotten until 1963, when someone found a unknown room behind a house wall, which led to the rediscovery of subterranean Cappadocia.
Other underground worlds:
- Naours is a city beneath a forest in Northern France that contains 2 miles of tunnels and at least 300 rooms. It dates to the third century.
- Miners in 13th-century Poland dug out a huge living area while working on the Wieliczka Salt Mine. The site includes chapels and a replica of Da Vinci's "Last Supper."
- The Shanghai Tunnels lie beneath Portland, Oregon, and although mostly closed off today, still contain tunnels once used by bar owners to bring alcohol from ships.