On the south-eastern edge of Juodlė lake there is a low marsh – transition marsh ecosystem, which can be seen along the Juodlė cognitive trail. They formed by flooding a stream flowing from the lake. Low marshes, as well as high marshes and transition marshes, are very important wetlands, an important habitat for many plant, fungi and animal species. Large wetlands not only affect the local microclimate, but also maintain a constant humidity regime in the wider area. After winter and rain, they accumulate water like large sponges, and then slowly “give it back” to springs, rivers and streams. Wetlands are not only marshes, but also wet forests – black alder bogs, swamps and quagmires, overflowing meadows, shallow and overgrown lakes, swampy river deltas and shallow sea area. Wetlands can be both natural and man-made. Wetlands also play an important role as natural filters, as they purify water from heavy metals and nutrients that leak from agricultural lands. Bogs and other wetlands with wooden footbridges are interesting places to explore and observe nature.