The January 11, 1771 Park is placed right in front of Mount Piz, where more than two centuries ago a ruinous event changed forever the fate of the valley and all the villages that stood near the Cordevole stream.
On the evening of January 11, 1771, a huge landslide broke off from Mont Spiz, blocking the course of the Cordevole stream and forming the Lake.
The landslide hit the villages of Riete Marin and Fusina causing forty-nine casualties. Soon after, due to the rising water level, the inhabitants of the villages of Sommariva, Torre, Peron, Sopracordevole, and Costa also had to leave their homes and take refuge in higher areas.
Only Alleghe, which stood on higher ground, was saved from submergence and thus also gave its name to the newly formed the Alleghe Lake. The village remained isolated; there was no possibility of access either from the Royal Road that connected with the Austrian State or southward in the direction of Belluno.
In a letter dated January 15, the Podestà of Belluno, Rizzardo Balbi, communicated the news to the Most Serene Prince of Venice, asking for help and suggesting possible remedial action.
In the months immediately following the event engineers and technicians were assigned to look for solutions to the increasing rise of the lake, but, at dawn on May 1, a new landslide broke away from Mount Spiz and ruined in the water basin below causing a huge wave that caused the death of three more people, flooding houses, land, the Rectory and the Church.
It took years of work before the road system was completely restored; the Cordevole stream resumed its course downstream, houses and church were rebuilt and restored, and the town of Alleghe has since been able to boast of this body of water reflecting the majestic Civetta mountain face.
The park houses a horizontal sundial that marks true solar time and the sunrise and sunset times according to the time of year. The operation is described in a specially prepared explanatory panel.