10km Race Medemblik 2026 — IJsselmeer Zwemmarathon

In the quiet hours before dawn in Medemblik, the local community gathers with a focus that reflects the rigorous nature of this marathon. The organization, led by Joost, Kees, and Rob, manages the event with the precision of a logistical operation, ensuring every swimmer is paired with a dedicated support boat for the 22-kilometer crossing from Stavoren. While those seeking a shorter commitment might look toward the IJsselmeer Zwemmarathon in August, the participants here prepare for a full-day endeavor across the IJsselmeer. This event is a test of endurance where the rhythm of the stroke is dictated by the vast, open water.

Historical currents and landmarks

As swimmers move toward the finish, they pass through waters rich in regional history. The route approaches the shoreline near the Kromme Leek, an ancient peat river mentioned in records from 985 AD, which eventually discharges into the lake. Near the entry to the harbor, the course passes the site of the Jewish cemetery established in 1765, where 33 headstones remain as a silent witness to a community largely displaced by 1942. Further along, the coastline is defined by the Pilot Polder Andijk, constructed in 1926 as a prototype for the larger Zuiderzee Works and inaugurated by Queen Wilhelmina to test agricultural viability on reclaimed land.

The final approach

The history of Medemblik is inseparable from its defensive and cultural heritage. Swimmers head toward the finish line near Kasteel Radboud, a fortress built in 1286 by Count Floris V. The castle walls have stood through centuries of conflict, including the 1517 raid by the Arumer Zwarte Hoop, a pirate fleet led by Pier Gerlofs Donia. Within the town, the Bonifaciuskerk marks the site where the composer Jan Pieterszoon Sweelinck was married in 1590. On the Kaasmarkt, the 1878 barometer monument continues to stand, serving as a rare piece of Dutch meteorological history. The finish line in Medemblik represents the culmination of this long-distance effort, with the support teams guiding swimmers into the harbor as the town greets the arrival of the marathon participants.