The back and forward lakes Stubensee (lit. Lake Stuben in German; ) are located 2,423 m above sea level in the back part of the Pflersch valley, which is a left side valley of the Eisacktal. Similar to the Grünsee, one has to go by car until Ochsenalm (an alpine pasture) and then travel northwards high up route 6 until the lakes are reached after about four kilometers. At the forward lake, there is a snack station called Magdeburger Hütte (German for Magdeburg alpine refuge), which is named after the city in Germany.
Both lakes have a very good water quality (A grade). As typical mountain lakes, the water remains refreshingly chilly even on hot summer days at max. 12 ðC. While the back lake is only supplied by rain or melting snow, the forward one is supplied and drained by the Hochtalbach (A grade quality / rapid). The creek has a length of about 1.65 kilometers and belongs to the source rivers of the Fernerbach. Both merge near the Ochsenalm. Both lakes give also a protected, untouched living space to trouts and carps.