Archaeologists in Turkey have discovered what they believe is the largest underground city in the world to date. The ancient underground city which includes a sanctuary, storage areas, water wells and passages with tunnels is located in the Midyat district of the Mardin province, in southeastern Turkey. The underground city, which has been called Matiate (meaning ‘city of caves’), was discovered accidentally during the cleaning and conservation of historical streets and houses in Midyat. In a project that started in 2019, workers were cleaning a cave when they discovered a passage. Excavation work then revealed a multitude of rooms and other tunnels leading from it, as well artifacts and wall murals.