Underground city was discovered in otherworldly region of Cappadocia . It is believed to consist of at least 3.5 miles ( 7km ) of tunnels and rooms . Geophysicists studied 113 metres ( 4 km ) area using seismic tomography . Study suggests underground corridors may be 371ft ( a 1.5 mile ) deep .
Underground city was discovered in otherworldly region of Cappadocia . It is believed to consist of at least 3.5 miles ( 7km ) of tunnels and rooms . Geophysicists studied a 1.5 mile ( 4 km ) area using seismic tomography . Study suggests underground corridors may be 371ft ( 113 metres ) deep .