Rauvolanlahti is a reed-fringed bird sanctuary on the edge of Turku, linked with the Katariinanlaakso nature reserve. Boardwalks and nature paths lead through wetland and woodland, with birdwatching towers along the way.
It is a quiet, practical escape from the city rather than a showpiece attraction. Wear shoes that can handle damp ground, especially after high water, and bring binoculars if you care about the birds more than the walk.