Here is another Karst phenomenon among the most important in Italy: located on Mount Cervati, at over 1000 meters above sea level, the Vallivona sinkhole is a real chasm, with sides up to 100 meters high. The path to reach it does not let visitors foresee anything of the spectacle it reserves. The sinkhole is in fact located at the mouth of a long tunnel — about 500 meters — which goes into the darkness of the mountain. From the entrance, you can hardly see a dim light at the bottom, but really no clue of what awaits the visitor once he reaches the end of this tunnel.

There suddenly visitors get the bottom of the sinkhole: very high limestone sides are covered with rich vegetation, the ground is a carpet of butterbur. Looking up, the edge of the chasm appears surrounded by the canopy of large trees. And last but not least, from a crack in a side like a cut in the rock, the water of a small waterfall gushes with a jump of several meters: the show is pure beauty and emotion. Jules Verne lovers could easily call it Journey to the Center of the Earth.

The sinkhole is the result of the work of water over millions of years. The flysch rock on which the water flowed dates back to the Miocene: the sinkhole was a crossing cave, the path of the water can be read in the fossil ducts placed above the active ones. This made it possible to understand that the water of Vallivona is nothing more than the high way of the Bussento river, the wonderful river that loves to play hide-and-seek along its entire path, giving a series of springs and sinkholes in less than 40 km of length.