Riserva Naturale del Lago di Canterno

The Riserva Naturale del Lago di Canterno protects a karst lake and surrounding wetlands on the southern slopes of the Monti Ernici. Established in 1997, the 1,824-hectare reserve spans five municipalities: Ferentino, Fiuggi, Fumone, Torre Cajetani and Trivigliano.

Why it matters

Lake Canterno's changing water level reflects the geology and history of the basin. Before the early twentieth century, water periodically drained through the Pertuso sinkhole. After the outlet became blocked, the Società Romana — now ENEL — stabilised the lake for hydroelectric use. The resulting wetland supports shoreline and aquatic habitats within a broader landscape of hills, woods and karst features.

What to notice

As the lake level changes, low water can expose small islets and a peninsula; when it rises, the shoreline habitat contracts. The reserve's birdlife includes herons, egrets, cormorants, grebes, coots and moorhens, while birds of prey use the wooded slopes. Chestnut woods extend into the area from the Fiuggi side, and the reserve also contains dolines, caves and swallow holes.

Context and history

The lake occupies a dolina basin in the Ernici foothills, mostly within the municipality of Fumone. It measures about 1.7 kilometres in length and roughly 700 metres across. Fragments of wooden piles believed to be from prehistoric lake dwellings were recovered during the digging of an artesian well. The reserve was established by regional law in October 1997 and is managed within Lazio's protected-area system.