The Triatlón de Donostia begins in La Concha, the bay directly before San Sebastián, with views of Santa Clara Island and the surrounding hills from the water. This Olympic-distance triathlon takes place annually in June in Gipuzkoa, featuring a 1.5 km swim, 40 km bike, and 10 km run. As Spain's oldest Olympic-distance triathlon, it offers a distinct atmosphere compared to newer races designed primarily for tourists.
The swim takes place in the protected waters of La Concha before competitors head inland into the Basque countryside. The cycling course is known locally as rompepiernas, or “leg-breaker,” with frequent changes in rhythm rather than extended flat sections. Athletes must pace themselves on the ascents before returning to the coast. The event, also known as Memorial Onditz, is organized by Atlético San Sebastián, with its base located on Paseo de la Concha in Donostia / San Sebastián.