Zegama-Aizkorri Mendi Maratoia is a May skyrunning race held in Zegama, Basque Country, Spain. Its marathon-distance mountain course ascends Aizkorri before returning to town. The SkyMarathon covers 42.195 km with 2,736 meters of elevation gain, presenting steep mountain challenges instead of a road-race pace. Established in 2002, the event later introduced a 5 km Vertical Kilometer; both are part of the Skyrunner World Series.
The SkyMarathon begins in Zegama, ascends the Aizkorri massif to reach Aizkorri at 1,551 meters, and concludes back in Zegama. Its winners demonstrate the race's high level of competition: Kilian Jornet holds the fastest recorded SkyMarathon time, and the event attracts elite mountain runners internationally. Although the COVID-19 pandemic canceled two editions, the race has since resumed its established format: a demanding mountain marathon, a short uphill race, and a Basque village serving as the weekend's focal point.