Derinkuyu, Türkiye
Derinkuyu (Turkish pronunciation: [deˈɾinkuju]), also known as Malakopi, is an ancient multi-level underground city near the modern town of Derinkuyu in Nevşehir Province, Turkey, extending to a depth of approximately 85 metres (280 ft). It is large enough to have sheltered as many as 20,000 people
together with their livestock and food stores. It is the largest excavated underground city in Turkey and is one of several underground complexes found throughout Cappadocia.
Listen to the audio guide for Derinkuyu Yeraltı Åehri Free on WIP — starts by itself when you arrive, even with the screen off