Lake Formarinsee is a 1793 m high mountain lake in the Lechquellen Mountains. Lake Formarinsee is not far from the starting point of the Lechweg. The mountain lake lies near the Rote Wand mountain, the second highest mountain of the Lechquellen Mountains. The Red Wall is named after the particularly conspicuous layers of red rock in the southern wall of the mountain. South of Lake Formarinsee lies the Freiburger Hut, a 1,931 m high mountain refuge of the Alpine Club. Northeast of Lake Formarinsee lies the Formarinalpe hut. Near Lake Formarinsee, the Formarinbach rises, but it does not originate from the mountain lake, but below the Red Wall. The Spullerbach creek and the Formarinbach creek merge a few kilometers before Lech am Arlberg to the Lech River.
