Formed following a calderic collapse of some volcanoes, it belongs to the Volsini mountains and is considered the largest lake of volcanic origin in Europe.
It boasts an almost completely uncontaminated natural environment and is one of the few large Italian lakes to be completely suitable for swimming.
It is precisely the surprising cleanliness of its waters that has guaranteed an extraordinary development of its animal and plant species.
Oval in shape, it has two islands: Bisentina and Martana. The Bisentina
island largest by surface is typical for its unspoiled nature and its enchanting views. The Martana island, located in front of the center of Marta, would have guarded the remains of Santa Cristina with the intention of preventing them from falling prey to the Barbarians.
Unfortunately not open to the public because it is privately owned.