At SE of the basin that houses the Three Lakes, there is Lake Scuro which occupies the eastern part of a mountain circus. It has an extremely irregular shape. At the inlet, it forms a wet area like a delta that towards the center of the lake divides it into two small basins.
The Lago Scuro delle Malghette is a shallow lake with expanding seabeds that host the cladocerus Streblocerus serricaudatus among the zooplankton organisms. This small organism, characteristic of stagnant waters and small pools and basins, is not very frequent. It was found for the first time in Italy in the Lake Colbricon Inferiore at the beginning of the last century. Among the lakes in the Park it was found only in Lake Scuro at Malghette and in Lake San Giuliano. The emissary is located on the northern shore and its waters reach those in the Malghette Lake further downstream. The water color, rather dark, gives the basin its name.