With a surface of just over a square kilometer, the enchanting Lake of Letino was created at the beginning of the twentieth century in order to feed the hydroelectric power station of Prata Sannita.
It is an artificial lake, created in the 1960s to power the electricity station of Capriati al Volturno.
It rises at the foot of Mounts Trebulani, at 86 meters above sea level, in the territory of Calvi Risorta.
On its shores violets grew, and this is why the Greeks called it Clanis. The River Clanis rises on Mounts Tifatini.