One of the most attractive open water swimming marathons in Serbia is being held on the river island of the Sava River in Belgrade itself. The joint start for three races is a unique event for all lovers of sports and swimming. In addition to the attractive location, the marathons on Ada Medjica are also sporting challenges, as they are the only open water races where one part of the river Sava is swum upstream. They swim around the island of Ada Medjica. The marathons are held within the Association for Long-distance and Master Swimming of Serbia.