Långholmen (a small island just outside Södermalm) is perfect for swimming. The island is full of cliffs, jetties, inlets and small bays. The beach has a beautiful, shallow jetty with a sandy beach and a lawn. Families with children get together to swim and have picnics on the grass. There are trees nearby, great for climbing and providing lots of different hiding places. Just getting there is like being in an Astrid Lindgren fairytale, passing the quaint houses and beautiful gardens.