The complex is one of the most spectacular underground excursions, a sort of pristine parallel world in which nature has created a unique ecosystem over millions of years.
Millions of years ago the Sentino river made its way under the mountain, inside large faults in the limestone rock. Its cold waters, meeting the sulphurous ones, increased the dissolution of the limestone, creating enormous voids and generating the whole system of caves.
The Frasassi Caves extend over a length of over 20 km. The part that can be visited is a path of about 1500 meters. The most important areas are:
- GREAT CAVE OF THE WIND OR ABYSS OF ANCONA: the huge cavity could contain the Milan Cathedral
- ROOM 200: a corridor of 200 meters
- DELE CANDELINE ROOM: numerous small cylindrical stalagmites resemble candles
- WHITE ROOM
- SALA DELL ‘ORSA
- HALL OF INFINITY
- ROOM OF THE PAGLIAI
The combination of water and limestone creates concretions of considerable size that are divided into stalagmites, columns that grow progressing from the bottom upwards, and stalactites, which descend from the top to the bottom.
Among the most famous Stalactites and Stalagmites discoveries that can be admired during the visit are: THE GIANTS, THE CAMEL, THE DROMEDARY, THE BEAR, THE MADONNINA, THE SWORD OF DAMOCLE (the largest stalactite 7.40 m high and 150 m in diameter), THE SMALL NIAGARA WATERFALLS, THE SLICE OF BACON (light pink), THE SLICE OF LARD (white due to the calcite), L’OBELISCO (stalagmite 15 meters high), THE CANNE D ‘ ORGAN, THE CASTLE OF THE WITCHES.
Inside the caves there is no natural light, the temperature is constant at 14 degrees and 67 species of animals have been recorded.
In 2017, the Frasassi Caves became a UNESCO World Cultural and Natural Heritage.