Copenhagen's inner harbour has been clean enough to swim in since the late 1990s — a remarkable achievement for a major European city. Several floating harbour baths (havnebade) are open in summer, the most popular being Islands Brygge Havnebad on the south harbour and Kalvebod Bølge further west. The Islands Brygge baths have pools, platforms, and diving boards built on floating pontoons and are free to use.
Swimming in the harbour is one of Copenhagen's defining summer activities. The water temperature reaches about 22°C in July and August. The baths are open from around June through August and get very busy on warm days, so arrive early or in the evening.