The lake Anterselva ( Antholzer See in German, also Untersee ) is a small lake Alpine situated at 1642 m in the valley of Antholz (a side of the Pustertal ).

The lake, surrounded by coniferous woods, was formed following the damming of the Anterselva stream due to landslides detached from the mountains above; it is located within the Vedette di Ries-Aurina nature park, in the municipal area of Rasun Anterselva (in the province of Bolzano ), about 97 km from Bolzano and 17 km from the Val Pusteria state road.

The road that goes up the Anterselva Valley, after the lake, continues towards the Stalle pass, a pass on the alpine watershed that leads to Austria, in the Defereggen valley (due to the narrowness of the roadway, the section between the lake and the pass is open one-way alternating, regulated by a traffic light system: access in each direction is allowed only for a quarter of an hour every hour).

Around the lake, there are some bunkers of the Anterselva Mezzavalle-Lago di Anterselva barrage of the Vallo Alpino in South Tyrol, built to defend the Italian territory from a hypothetical invasion by German troops during the Second World War.

The legend of the lake, one of the many sagas of South Tyrol, tells that one day a beggar stopped in the fields of three rich farmers to whom he asked for alms. The three miserly peasants refused and chased him away empty-handed. The angry beggar said, "Within three days behind your house, a small fountain will appear and your eyes will open!" After nothing happened in the first two days, on the third day behind each farm a fountain had formed which gradually increased its capacity until it carried away the three farmers and their families. In that place, the Anterselva lake was formed.