The Pian del Re area which is part of the Unesco Mab, Monviso’s cross-border biosphere reserve, occupies 465 hectares around the Po’s springs, located at 2,020 meters above sea level and at the foot of the Monviso. The richness of water and the morphology of the soil have given rise to a bog, a habitat of particular botanical interest, where there is a rich variety of species, among which stand out “fossils” of glacial flora dating back to two hundred thousand years ago.
It is also the territory of a rare and small endemic amphibian, the black salamander of Lanza.

In 2017 a team of Canadian, Estonian, Irish scholars funded by National Geographic conducted a study consisting of small excavations and land surveys to show that Hannibal passed through here almost 2200 years ago.
According to William Mahaney, professor emeritus of the University of Toronto in Canada, Annibale entered Italy via the Colle delle Traversette, a pass at 2950 meters separating Piedmont from the French Guil Valley.
Studies have shown a dark layer about 30 centimeters deep, composed of organic material that emanates a bad smell. Probably it comes from horse dung, present in massive numbers and not explained in normal conditions.