OPEN WATER SWIMMING AT ITS PUREST
Are you ready for the ultimate endurance challenge in the Dutch IJsselmeer?
Rondje Pampus is far more than a standard open water swimming event. It is a battle against the elements—where the wind, the swell, and the sheer vastness of the horizon transform every stroke into a unique maritime adventure. Whether you are a seasoned competitive swimmer or a triathlete looking for the perfect training ground, swimming around the historic Fort Island Pampus offers an unparalleled experience you won’t find anywhere else in Europe.
Under our 2026 motto, ‘Experience nature in open water’, we are proud to celebrate the 15th anniversary edition of Rondje Pampus, taking place on Saturday 25th July and Sunday 26th July 2026. What began in 2011 as a passion project for a small group of nature enthusiasts has evolved into a hallmark of the Dutch sporting calendar.
But we swim with a greater purpose. Following our previous support for pioneering projects like the Fish Migration River, this year we are diving deep to protect underwater biodiversity.
Swimming for a sustainable future! Whether you are swimming for leisure or competing for a podium finish, every stroke helps protect the IJsselmeer ecosystem. A portion of the proceeds from this jubilee edition is dedicated to fundamental research by Wageningen University & Research (WUR). Their study into the current state of the aquatic ecosystem is vital for driving nature restoration and sustainable water management. Together, we ensure a healthy, living, and vibrant IJsselmeer for generations to come.
Sustainable water management
Water is the lifeblood of our planet, yet global aquatic systems are increasingly under threat. Wageningen University & Research (WUR) is at the forefront of developing resilient, nature-based solutions to restore the balance between humanity and the environment. By translating fundamental science into tangible action, they contribute directly to climate resilience and the preservation of vital ecosystems. Science meets the surface!
WUR researchers bridge the gap between academic theory and societal impact, collaborating with governments and conservation bodies. Their expertise is essential for turning complex ecological challenges into opportunities for restoration. Through an interdisciplinary approach, they develop strategies to improve water quality and ensure that the interests of both nature and society are harmonised.
Specifically, WUR is investigating how nutrient levels and climate change affect the underwater flora and fauna of the IJsselmeer. The goal? A water-positive society where healthy waterways support flourishing ecosystems. By supporting Rondje Pampus, you are directly funding the science required to safeguard the waters we love to swim in.
UNESCO World Heritage setting
Rondje Pampus takes place at one of the most evocative locations in the Netherlands: the man-made Fort Island Pampus. Situated in the IJmeer, just a stone’s throw from Amsterdam, this historic stronghold serves as the heart of our event. Completed in 1887 as a strategic component of the famous Defence Line of Amsterdam, the fort was originally designed to defend the entrance to the city from naval incursions.
The structure itself is a masterpiece of Victorian-era engineering. The fort rests upon a staggering foundation of 4,000 wooden piles, each eleven metres long. This oval, two-storey fortress, crafted from brick and concrete, remains an imposing monument to architectural ingenuity.
The name “Pampus” is steeped in maritime lore; in the Dutch Golden Age, ships would often lie “voor Pampus” (stronaded) in the shallows, waiting for the tide. Today, as a UNESCO World Heritage site, the island is a place where military history meets modern culture. For our participants, it provides a cinematic backdrop where athletic performance and historical heritage collide.
Secure your entry to Rondje Pampus 2026
At Rondje Pampus, we swim with a clear objective: the protection of the open waters we cherish. Following the success of our 2025 edition, which supported the Koopmanspolder, your entry fee for 2026 will fund critical research by Wageningen University.
Registration for the 15th Anniversary Edition is now officially open. Don’t miss your chance to brave the elements on 25th–26th July 2026. Whether you are an ironman triathlete honing your skills or a wild swimmer seeking a new horizon, this is an investment in the sustainability of the IJsselmeer.
Standard Entry: Click on the Entry Ticket 2026 button and secure your place via our webshop.
KNZB Competitive Entry: For members of the Dutch Swimming Federation (KNZB) looking to compete in the official race, please select the KNZB Entry Ticket 2026 below. A valid KNZB start number is mandatory for this category.
Rondje Pampus 2026 is made possible in part by the following partners and collaborating organizations of the Rondje Pampus Foundation:
If you’d like to stay up to date on the latest news about Rondje Pampus, follow us on WhatsApp or social media. You can find more information about the terms and conditions, the rules, and your privacy here. If you have a question about the Rondje Pampus 2026 open-water swimming event, please use the contact form on our website.
KNZB Open Water competition
For ambitious athletes, Rondje Pampus once again hosts an official KNZB Open Water Swimming Competition. This is a prestigious fixture for competitive swimmers, as the race counts towards both regional and national rankings. It is the definitive opportunity to climb the leaderboard while navigating the iconic setting of the IJsselmeer.
The course consists of a challenging 2,700-metre circuit, comprising three tactical laps around the island. To ensure a fair and safe environment, the race is overseen by official KNZB marshals. The starting gun will fire at 09:00 on Saturday, 25th July 2026.
Rondje Pampus Virtual Challenge
Can’t make it to the IJsselmeer in person? You can still be part of the mission. The Virtual Rondje Pampus Challenge allows you to participate at your own pace, wherever you are in the world. Whether you swim 900m, 1,800m, or 2,700m in your local pool or local wild swimming spot, your effort counts.
Why Join the Challenge?
- Win Prizes: Log your swim via your sports watch and share it in our Strava Club for a chance to win one of ten free entries to the 2027 event.
- Make an Impact: Raise awareness for aquatic conservation and sustainable water use.
- Community: Join a global network of open water swimmers and nature lovers.
contact us
Have a question about the event? We would love to hear from you. Please complete the form below, and our team will get back to you shortly. For the latest updates, follow us on Instagram, Facebook, LinkedIn, and WhatsApp.
The Rondje Pampus Foundation is the organizer of Rondje Pampus. You can find more information about the foundation here on the website (in Dutch).
RONDJE PAMPUS FOUNDATION
Weesperzijde 142
1091ET Amsterdam
The Netherlands
Chamber of Commerce: 85285528
