Derinkuyu is the largest ancient underground city in Cappadocia, Turkey. In the multi-level underground complex there were bedrooms, bathrooms, kitchens, food warehouses, wells, oil and wine presses, as well as churches, schools, stables and tombs. Ventilation shafts brought air in from above, and smaller ducts distributed it throughout the entire city. Derinkuyu may have been a refuge for 20,000 people.
The city of Derinkuyu provided security against Muslim Arabs during the Byzantine era. In the 14th century, Christians continued to seek refuge there during the Mongolian incursions. During the Ottoman era, the city was used as a refuge from repression by the Turkish Muslim rulers. Even in the early 1900s, the local Cappadocian Greeks still used underground cities to avoid persecution.
