Zegama-Aizkorri

Zegama-Aizkorri

Zegama-Aizkorri is a 42K mountain marathon with 2,736m D+ through the Aizkorri range in the Basque Country. It is the most legendary skyrunning race in Spain and one of the most prestigious on the world calendar. Held in May from Zegama (Gipuzkoa).

Zegama-Aizkorri is not just a race — it’s a myth of trail running. Since its first edition, this event has become a world benchmark for skyrunning, drawing the international elite to a small village of barely 1,500 inhabitants in Gipuzkoa.

The course

The Zegama-Aizkorri course is a 42K marathon with 2,736m D+ through the Aizkorri range. It includes the climb to Aizkorri (1,528m), the Aketegi ridge and the San Adrián tunnel.

Runners start from Zegama and follow a circuit ascending and descending the main peaks of the Aizkorri range:

• Aizkorri (1,528m) — The highest point in the Basque Country
• Aketegi Ridge — Technical traverse with exposure
• San Adrián Tunnel — Historic medieval pass
• Sancti Spiritus — Legendary climb with wild crowds

The cathedral of skyrunning

Zegama-Aizkorri is considered the cathedral of Spanish skyrunning. The men’s record stands at 3h42min (Kilian Jornet) and the women’s at 4h22min (Maite Maiora). This is a race where technique matters more than endurance.

Kilian Jornet, Jim Walmsley, Stian Angermund and the world’s best female runners have competed here. The Zegama crowd is legendary: thousands of spectators cheer from the ridges and mountain passes, creating a unique atmosphere.

Technical terrain

Zegama’s terrain includes exposed ridgelines, wet grass, limestone scree and forest trails. Poles are NOT allowed. Lightweight shoes with grip on wet grass and rock are essential.

The race combines fast forest trails with technical ridge sections where hands are needed. The wet grass typical of the Basque Country is particularly slippery, making shoe choice critical — read our best trail running shoes guide for skyrunning footwear advice. The descent from Aizkorri to Aratz is one of the most technical downhills on the skyrunning circuit.

Vertical Kilometre

Alongside the marathon, Zegama-Aizkorri includes a Vertical Kilometre of 4.5 km with 1,050m D+. It’s an explosive event held the day before the marathon.

The Zegama VK is one of the toughest events on the Spanish skyrunning circuit. In just 4.5 kilometres runners climb 1,050 metres of elevation, with gradients exceeding 50%.

Use our pace calculator to plan your race strategy on this legendary course, and explore more races in the Basque Country.