The Mūša Tyrel Cognitive Trail is listed in the Lithuanian Book of Records as the longest boardwalk in a marsh. The boardwalk is 5,775.87 m long. Together with the natural ground trail, the total length of the trail is more than 6 km. The trail leads through the Mūša Marshes Telmological Reserve (area 1,675.6 ha). This natural complex in northern Lithuania consists of raised bogs, transitional bogs, fens, peat bogs, and wet forests. The Mūša and Juodupis rivers begin in the southern part of the marsh, while the natural Lake Miknaičiai and many small lakes are located in the eastern part. The Mūša Marsh is also a Natura 2000 site. The marsh is home to many protected plant species, including Baltic and narrow-leaved marsh orchids, marsh cinquefoil, and common tufted sedge. Rare birds live here, including corn buntings, teals, gray herons, and black grouse, and flocks of migrating white-fronted geese and bean geese stop here.