At a short distance from the Castle of Zumelle and surrounded by woodland, it is a small gem with wonderful crystal-clear water.
The well-marked path number 2311 starts from the large parking area of the Castle of Zumelle and descends along a steep slope dotted with artistic installations, following the bed of the Rui stream, immersed in a suggestive environment, far from the rest of the world.
The layered rocks surrounding the cavity create different shades of gray and white, while the water, which cascades inside through a small waterfall, is clear and crystalline with the typical blue color from which this beauty gets its name.
It is impossible not to be fascinated by the chromatic spectacle that changes according to the season and the angle of the sun's rays that reflect on the surface of the water. The Blue Grotto is also a sought-after destination for canyoning enthusiasts, the only ones allowed to dive into this natural wonder.
Nearby, there is the Lombard church of San Donato and the ancient mill for grinding grain.