Thames Ring 250

The Thames Ring 250 is an iconic 250+ mile ultramarathon loop starting from Goring, following the River Thames into London, then along the Grand Union Canal and back down the Oxford Canal to the finish. Established in 2009, it was the first race of its kind, known for its challenging course and high difficulty, with a completion time limit of 100 hours. Checkpoints are placed every 25 miles, offering well-stocked aid stations and rest tents, though the clock continues running during breaks.

The event features tracking, first aid support, and awards finishers with a distinctive heavy medal. The course record is just under 60 hours. Visit the organization's website for the most recent information.