IJseelmeerzwemmarathon or IJseelmeer Zwemmarathon is one of the world’s classic marathon swims that was recognized as an (Honor Contributor – Organization) by the International Marathon Swimming Hall of Fame in its Class of 2020. It is held annually from Stavoren to Medemblik in IJseelmeer, the Netherlands. IJsselmeerzwemmarathon is a 22 km marathon swim from Stavoren to Medemblik in IJsselmeer in the Netherlands. The Ijsselmeer was formerly in the ocean, but it is now a large lake. Ijsselmeer can develop very difficult conditions with the winds is usually held on the second Saturday in August with a competitive field. Its 50th annual race was held in 2019. The event was initially recognized for merit by the International Marathon Swimming Hall of Fame in 2007 and is one of the World’s Top 100 Open Water Swims. Individual escort boats are required and some prize money is offered that has served as the Dutch Marathon Swimming National Championship.