A network and mosaic of water
The Marittime Alps is one of the richest alpine sectors in natural bodies of water , almost all lying in depressions formed by the Quaternary glaciers or blocked by the moraines they left behind. The latter is the case of the Lago delle Rovine, located at 1535 metres above sea level in the Gesso Valley of Entracque: as the name implies, it seems to have originated from a disastrous landslide that in ancient times blocked the course of a stream. Today this lake no longer has its natural appearance, because it has been modified and reduced by the construction of the large Enel hydroelectric plant. To feed the underground power station two large artificial reservoirs were created : Piastra, located in the lower part of the valley, and Chiotàs, at the base of the eastern slope of the Argentera.Among the natural lakes, the most extensive is the Sella soprano lake (around 123,000 square metres), located in a rocky basin in the Matto massif at 2329 metres above sea level. A little smaller (about 107,500 square metres) is the lower Lago sottano della Sella (1882 metres). In Valle Gesso, other particularly beautiful lakes are: Lago del Vei del Bouc (2054 metres), above San Giacomo di Entracque, Lago Brocàn (2000 metres) near the Genova-Figari Refuge, the round Lago delle Portette (2361 metres) near the Rifugio Questa, the Fremamorta Lakes (about 2300 metres) near the Guiglia Bivouac hut, the lower Lago di Valscura (2274 metres) and the Lago del Claus (2344 metres). The latter is particularly striking because a narrow peninsula of roches moutonnées and an island emerge from the water. There are also numerous lakes in the Maritime area of the Stura di Demonte valley. The largest of them, the Lago soprano della Valletta (2231 metres), is located within the Park in the secluded Valletta di Aisone.
Regarding the altitudes, it should be noted that the two highest lakes in the Maritime Alps are both located in Valle Gesso. The highest of all is the evocative Laghetto della Maledìa, located at about 2900 metres near the peak of the same name, often cluttered snow and ice bound until late summer. Second in this ranking is the Lago di Nasta, at the foot of the peak of Nasta.
Transient phenomena such as waterfalls , mostly originate, like the lakes, from the erosive action of the ancient glaciers. You will find foaming waterfalls in almost all the valleys in the Maritime Alps. Among the most picturesque is the great Ischietto waterfall, located in a secluded secondary branch of the Valle Gesso di Entracque.
In compact rocks such as the gneisses of the Argentera Crystalline Massif, the erosion of ancient waterfalls has often given rise to narrow, deep gorges . In the Gesso Valley there are some very wild ones, such as those carved into the northern spurs of Mount Gelas.