It is an artificial basin built in 1959 to meet the growing water needs of the city, and still today it represents the main water supply of the city of Genoa and partly of Piacenza. For its realization it was necessary to demolish with mines the houses of two villages, Frinti with 15 houses and Mulini di Brugneto with two houses, causing great dissatisfaction to its inhabitants.
Over the years Lake Brugneto has become famous for a curious legend, told by the fishermen living around the shores of the lake and the inhabitants of the Val Trebbia: it is said that during the periods of drought it is reflected from the mirror of water the tip of the bell tower Of Frinti and that it may be possible to feel the tapping of his bell.
In October 2004, an underwater expedition was also organized to test the phenomenon, but the divers did not find any traces of this church after 3 hours of exploration and thus disrupted the famous "Legend of the Brugneto". Subsequently it was found that there has never been a true church in the village of Frinti, and that the photos spread in the local newspapers were just photomontage to attract tourists. Nonetheless, the most fervent advocates of legend say that divers are wrong.
Though the legend is best known, few know what really happens in the Brungneto basin during some particular periods of the year. Being an artificial invasion, and therefore regulated by the opening and closing of the dams, due to poor precipitation or increased water consumption, it may happen that its level decreases, revealing the remains of the past.
It is precisely in this circumstance that you can see the ruins of the two villages of Frinti and Mulino del Brugneto that emerge from the water. The phenomenon has been certified in a fascinating photographic reportage and is well documented by the folding edited by the Antola Natural Regional Park. However, this is a unique, rare occasion since the basin is now full and it is not known when the level of the reservoir will fall again. The same president of the Antola Park said: "It happens rarely to observe the presence of the ruins of the countries with the naked eye. In some cases you have also been able to see the ancient Roman bridge, which has also suffered the same fate and was buried by water. "