It is a 4-kilometer-long trail around the lake Juodlė, in the Ilga River Landscape Reserve. It has 12 stops. Along the way, you learn about the landscape, the forests typical of the park, the most important forest habitats, swamps, and rare species of plants, mushrooms and animals. There are info boards and observation towers installed along the trail, as well as a wooden path leading to the middle of the swamp.