Seven Sisters Skyline 55K

The Seven Sisters on 19 September 2026 is an epic mountain running event in the Derryveagh mountains in Donegal, Ireland.

This event has become Ireland’s Premier mountain running event, and is part of the UK-Ireland National Skyrunning series. It is also Ireland’s largest mountain running event.

The iconic Seven Sisters Skyline is a 55km Ultra with 4,000m ascent and is regarded as the toughest in Ireland. The route runs along the top of all of the Seven Sisters in the Derryveagh mountains from Errigal to Muckish. The course is renowned for its variability in terrain and amazing beauty.

The festival also includes the Seven Sisters Sky Challenge, a 30km with 2,100m ascent; plus the Altan Castle 16km distance.