Lake Tovel: The Lake That Once Turned Blood-Red

There's a strange story tied to Lake Tovel, in the Val di Non: for decades, every summer between July and August, its waters turned an intense red, almost the color of blood. The phenomenon was caused by a microscopic alga, Glenodinium sanguineum, which thrived in the lake's cold waters and colored the surface in spectacular fashion. Then, in the 1960s, the red almost entirely vanished — not because of a chemical change in the water, as once believed, but because of a decline in nutrients linked to the gradual abandonment of high-altitude summer grazing — and it never returned with the same intensity. The lake has remained emerald green, beautiful, and nearly forgotten.

How to get there and what you'll find

Tovel is reached from Tuenno, in Val di Non, via a forest road of about 12 kilometers climbing through red spruce woods. In summer, a shuttle service limits private traffic: you leave your car in the valley and take the bus up. The lake sits at 1,178 meters elevation in the heart of the Adamello Brenta Nature Park. The shoreline is entirely walkable on a flat path of about 3 kilometers: an hour and a half with photo stops. The water is crystal-clear and cold — around 12°C even in August.

The surrounding forest and park trails

From the lake, trails lead to the Rifugio Tovel (a 20-minute walk from the shore) and toward the more challenging peaks of the northern Brenta range. The forest surrounding the basin is one of the most intact in Trentino: beeches and red spruces of notable size, with the documented presence of roe deer and, more rarely, brown bears from the Adamello Brenta Park. The fountains at the shore offer the freshest water. The refuge serves simple dishes at reasonable prices: canederli, polenta with mushrooms, apple cake.

The Val di Non context

The Val di Non is famous above all for its apples — it produces about 30% of Italian apples — but hides much more: the Gole del Rio Sass (a basalt canyon navigable by kayak or on foot), Castel Valer, the lakes of Santa Giustina. Tovel is the hidden jewel of this territory, visitable from May to October, with June and September as the ideal months to avoid peak summer crowds.