The Upper Lake is located at 929 m s.l.m., has a maximum depth of 10 m and a surface of 9 ha; the lower lake is located at 924 m s.l.m., has a maximum depth of 25 m and a surface of 13.5 ha. In the vicinity of the lower lake there are also two other tiny pools of water, called small lakes. The Upper lake feeds the Inferiore lake underground and the latter feeds the emissary of both lakes.
In winter, the Fusine lakes area is one of the coldest places in the Friuli Venezia Giulia region, and often there are the minimum temperatures in Italy that according to unofficial surveys on January 6, 1985 reached -34 ° C .
