Lake Sirino is a small natural reservoir in Basilicata located in a karst sinkhole at the foot of the mountain of the same name, in the municipality of Nemoli, at an altitude of 788 meters above sea level. The small lake, practically a pond, is slightly elliptical in shape and is perhaps the last remnant of the large Pleistocene lake that occupied the Noce valley.
The body of water, in ancient times much larger than the present five hectares of the winter flood periods, occupied the lake basin of the Noce in prehistoric times, along the present course of the river and widened upstream from the town of Nemoli reaching Lauria; from there, passing through Trecchina, it circled around the slopes of Mount Coccovello and the adjacent mountain ranges. The bottom and shores of the lake consist of limestone with flint nodules dating from the Triassic period and polychrome jaspers predominantly red, gray, brownish and white, called siliceous schists, from the Jurassic period.