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Afan Argoed Has the Rocky Mountain sponsored 20km singletrack Penhydd, Trail, and the highly technical trail known as 'he Wall'
Cym Carn Has the purpose build Twrch Trail and a visitors centre. It’s a stones throw from the M4 and only a few miles from the English border so it’s dead easy to get to.

Oh and there's a nice short DH course with road access to ride back up.

Coed y Brenin The heart of Welsh mountain biking with the famous Red Bull and MBR trails plus the Karrimor loop’s 38km of technical singletrack. It’s a training ground for world class racers