Grim Reaper Ultra Marathon

The Grim Reaper Ultra Marathon is a multi-distance trail running event held at the scenic Grimsthorpe Castle Estate in South Lincolnshire, UK. Scheduled for May 24-25, 2025, it offers solo race options of 10, 40, 70, and 100 miles, plus 40- and 100-mile team relays. The course features a fully marked 10-mile loop combining grass trails through ancient woodland, limestone tracks, quiet estate roads, and a disused Victorian railway line, with an elevation gain of about 550 feet per lap.

Runners can camp onsite, and aid stations provide limited supplies. The event emphasizes a friendly atmosphere suitable for all abilities, with mandatory kit for ultra distances and trophies awarded to top finishers. Visit the organization's website for the most recent information.