The Havsbad ("sea-bath") is a wooden bathing pavilion on the rocks at the western edge of Lysekil, the last surviving piece of the 1864 spa complex that put the town on the map. It still functions: changing rooms, a sauna, jetties to swim from, and a small cafe in season. The building itself is the attraction — gabled, ornate, gloriously over-engineered for a small fishing town.
You can swim here at any time of year if you can stand the water temperature. In summer it gets busy on warm afternoons; in October locals do brisk dips before retreating to the sauna. About a ten-minute walk west of the harbour along Strandvägen.