Maantielakso is the largest seasonal wetland of Kauhaneva-Pohjankangas national park. It is a basin where water level changes during seasons. In early summer there is a pond, in late autumn there is just dry sand. The water comes from the huge Kauhaneva mire and flows along the narrow Laksoneva mire to Maantielakso. There it seeps into the permeable ground, into the Pohjankangas glaciofluvial formation, where it turns into groundwater.