The lake is of glacial origin, with flat, overgrown shores and not very deep. Excluding the Gostynin area, it is currently, after the draining of the Kurpie Lake Serafin, the largest natural reservoir in the historical Mazovia. As the topography indicates, it used to be one whole with the nearby Lake Rydwan. Unlike the latter, it was not divided into ponds, although there are causeways on the shores that allow communication. The natural value of the lake is the great abundance of birds (there are over 180 species) and numerous species of protected plants. Beavers are also very numerous here. To the east of both lakes, there are ponds used as bathing areas, created on the site of a former gravel mine.