Our ancestors believed that mysterious spirits searched for victims in the swamps at night, and that such places were best left alone. Even today, most people still regard wetlands with reverential awe, even though it is in the wetlands that one can get to know unique nature untouched by man. One of them is Mūša Tyrelis in Žagarė Regional Park, which has the longest boardwalk in Lithuania. The trail is included in the Lithuanian Book of Records and covers almost 8 km. It is a real discovery for those who are interested in the ecosystem of swamps, as it provides a chance to get acquainted with the flora and fauna of the moorland in an untouched environment, and to enjoy the silence of the swamp inhabitants, such as grouse, common cranes and geese. The site is protected at the European level.