This trail of about 3 km circles a nutrient-rich lake within walking distance of central Naantali, mostly along the shore and through forest on the east side. The lake covers about 25 hectares, is 5.3 metres deep at its deepest, and its water level has been regulated since 1953. Spa activity grew up around the Viluluoto spring on its shore from the 1700s, and a 2003 survey recorded 26 bird species.
Two bird towers stand on the shore, one with a ramp. Depending on the season, the duckboards can be wet. The route suits children and picnics, and a notebook for logging visits is kept in a mailbox at the towers. Motorboats and vehicles on the ice are not allowed. There are two small car parks.