X-WATERS Sport-Marafon Fest 2026

X-WATERS Sport-Marafon Fest 2026 is an official amateur open-water swimming festival inside Sport-Marafon Fest at Nikola-Lenivets in Kaluga Oblast, Russia. The official event page lists 11 to 14 June 2026 on the Ugra River and offers public-entry swim distances of 3 km and 10 km.