Brecon to Cardiff Xtreme & Taff Xtreme Marathon

This 47.5-mile linear race takes on 11 summits and high points between Brecon and Cardiff, with around 2,680m of ascent. A true winter ultra marathon, it demands strong mountain running skills, solid navigation and excellent fitness. This event sold out in 2024 and 2025 and with limited places available, early entry is essential. The Taff Xtreme Marathon covers the second half of the Xtreme ultra route, running from Merthyr to Cardiff. At 26.2 miles with 1,300m of ascent, it’s a challenging winter marathon but one that is ideal for runners ready for a new trail challenge or a stepping stone into the world of ultra running.