The name of the Round Lake is due to its shape. The lake is located at an altitudine 2427 meters in the Vegaia Tremenesca mountain group. The point of departure is in San Bernardo in Val di Rabbi. Its shores consist of accumulation of stones among which the green of the vegetation often appears. Its waters, quite deep, are very clear and the bottom shows any little detail through a flickering blue filter: it is an unforgettable sight. Although the altitude, the lake guests many microscopic organisms.