Grotte di Pastena features extensive Mesozoic limestone formations

The Grotte di Pastena represent an extensive underground system formed by water erosion on limestone dating back to the Mesozoic era, approximately 50 to 80 million years ago. The cave network spans nearly one kilometer and is divided into two main sections: an active lower branch characterized by flowing water and a fossil upper branch containing various limestone formations.

Key geological features include the Sala del Lago Blu, which features a 10-meter waterfall cascading into a 5-meter deep lake, and the Sala del Salice Piangente, named for a column formed by the merging of a stalactite and a stalagmite. The cave system continues to undergo slow transformations through ongoing mineral deposition and water movement.