One entry to one of the caves of Frasassi was discovered by a farmer on June 28, 1948.
More entries were found in the 50s and 60s by members of the Italian Mountaineering Association (Club Alpino Italiano) from the neighboring towns of Jesi and Fabriano.
Large parts of the underground complex were discovered in the early 1970s. The total cave complex covers a distance of 13 kilometers.

From September 1974, part of the caves is open to visitors. A 1.5 km long route has been laid out over wide hiking trails and spacious stairs.
These tours are led by a guide in Italian, French, English or German.
The caves have become a major tourist attraction of the Marche region. More than 10 million people have visited the caves since opening up.
In addition to this route are a blue and a red speleological route for the advanced enthusiasts