The peat nature reserve (12.88 ha) is situated on the south of the village of Drewno (Nadleśnictwo Gołąbki – the Gołąbki Forest District). It was created in order to preserve the sources of the Gąsawka River for natural, scientific, and educational reasons. In the reserve there are many protected or rare species, e.g. marsh helleborine, spurge laurel, martagon lily, cowslip, baneberry, wild garlic, and lesser bladderwort. The dominant type of forest is riparian alder forest, which on scarps transforms into clusters of oak–hornbeam forest features.

In the reserve there is a natural forest walking path called “Dolina rzeki Gąsawki” [The Gąsawka River Valley]. It goes through picturesque forest areas that have been shaped for thousands of years by the meandering river. Its attractiveness is increased by numerous water pools. Issues relating to environmental protection and selected aspects of forest management are presented along the path. Along the 1.8-kilometer track there are 11 stops that are marked with information boards.