The Zêzere Swimrun is a swimrun race held in the Centro de Portugal region, following the undulating trails of the Grande Rota do Zêzere around the villages of Fontes and Souto, with breathtaking views over the Castelo de Bode Dam. The finish line is at Praia Fluvial da Aldeia do Mato.

The 2026 edition offers three distances: Standard (24.7 km total with 3.6 km swimming and 21.1 km running), Sprint (18.2 km total with 3.6 km swimming and 14.6 km running), and Experience (7.1 km total with 2.1 km swimming and 5 km running). Each distance includes multiple swim and run transitions, with the longest swim being 800 m and the longest run up to 9 km.

The race takes place in warm late summer conditions with water temperatures between 20 and 23 degrees Celsius and air temperatures around 28 degrees Celsius. The freshwater dam environment adds a safety factor due to lower buoyancy. Participants must manage their effort carefully on this demanding course.