The Frasassi Caves are the largest and best known in Italy. Discovered in 1971, were opened to the public only in 1974. So far have been explored only 13 km, but is expected that the caves rises to 35 km. Unfortunately, only 1.5 kilometers of the this crystalline earth is visible to the public. The Great Cave of the Wind is the largest in Europe, and is so wide that can even contain the Duomo of Milan. There are also the ‘”Ancona Abyss”, the “Hall of the Two “Hundreds, the “Grand Canyon”, the “Hall of Candles”, the “White Room”, the “Bear Room” and the Cave of “Infinity” . The tour lasts about an hour. Remember to cover yourself well because inside the cave you will find a temperature of 14 ° C!!