Open Swim Léman Prangins

In the winter of 1754, the philosopher Voltaire arrived at the Château de Prangins, seeking a quiet refuge to continue his work away from the tightening grip of European monarchs. He spent his months looking out over the expansive, deep waters of Lake Geneva, a landscape that has served as both a strategic boundary and a sanctuary for centuries. Long before the philosopher's arrival, the site was defined by the destruction of its original medieval fortress in 1293 by the Dukes of Savoy, a move that reshaped the power dynamics of the Vaud region. Today, swimmers entering the water at Prangins trace the same sightlines that occupied the minds of historical figures like Joseph Bonaparte, who briefly held the castle as a base for imperial loyalists before being forced into a hasty flight under pressure from the Allies.

The lake and the race

As you navigate the course, you swim past the mouth of the Promenthouse river, which flows down from the Jura mountains to meet the lake. This inflow introduces a subtle, shifting temperature gradient that serves as a living reminder of the catchment area feeding these depths. For decades, the horizon here was dominated by the imposing HBG time signal towers, which transmitted low-frequency data until their controlled demolition in 2012. Their absence has opened the view toward the shore, where the baroque architecture of the castle remains visible from the buoy line. The annual event, organized by OpenSwim, offers a wide range of distances from 400m to 5000m, accommodating both sprint specialists and endurance swimmers. Those looking to extend their experience in the Vaud region later in the summer will find the Trophée de la Harpe taking place just under a month later. Whether you are aiming for the 5k or a shorter distance, the lake environment reflects a history of royal exiles—including Charles I of Austria—and strategic maneuvers that have defined this stretch of water for generations.