Yr Wyddfa / Snowdon 24 is a 24-hour mountain endurance race on Yr Wyddfa, the 1,085-metre highest mountain in England and Wales. Located in Eryri (Snowdonia) National Park, the challenge is straightforward to grasp and difficult to execute: begin at the base of the mountain, ascend to the summit, descend, and repeat as many times as possible before time expires.
Solo participants can select from 50k, 100k, or 100-mile categories. The event is UTMB-indexed, serving as preparation or qualification for UTMB Mont Blanc. The existing solo record stands at eight complete ascents. Teams of up to five may compete in a relay, with each member contributing one or more climbs to the collective total. Some teams utilize this format for a club or workplace challenge, while others dedicate the day to fundraising for a charity.