Yr Wyddfa Sea to Summit
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Yr Wyddfa Sea to Summit mountain ultramarathon
This one-day Sea to Summit ultramarathon on 26 September 2026 takes participants from sea level to the summit of Yr Wyddfa as part of the Rat Race National 3 Peaks Trilogy. The course covers 29 miles (47 km) with approximately +5600 ft of elevation and is listed as a run/trek mass participation event.
The route begins inside Caernarfon Castle and finishes at Bron y Feds Uchaf, Rhyd Ddu (LL54 7YS). The course follows quieter southern approaches toward Beddgelert, ascends via the Watkins Path and South Ridge, and descends via the Ranger Path. The entire route is fully waymarked with bright orange arrows; a GPX file is also available.
The event is fully supported and uses professional on‑site medical teams, self contained vehicles and a private ambulance. Pit Stops provide water, hot drinks, salty snacks, sweets and fruit, and staff can supply basic medical assistance. Cut offs are set to a 3mph completion pace. At Pit Stop 2 there is a designated short route option that reduces the total distance to 20.5 miles with 5175 ft of ascent for those who miss that cut off.
Additional logistics include a bookable parking pass at the finish and a shuttle bus to the start, a transfer policy for entries, an optional third party Refund Protect product, and a finisher medal. Participants must be over 18 on the day of registration. Visit the organization's website for the most recent information.
