The lake Rohrsee lies, as the Lichtsee, north of the village Obernberg am Brenner at above sea level. On foot the lake can be reached by walking 500 m further east of Lichtsee. With an area of , it is about half as big.
Rohrsee shines with A grade water quality. Its environmental conditions, fauna and flora are almost identical with those of the Lichtsee. The Rohrsee is about two to five metres deeper.