5k Run Llanthewy Skirrid: Scenic Trails at Ysgyryd Fawr

Route Overview & Local Insights

Experience the rugged beauty of the Brecon Beacons on this 4.9km trail loop that packs a punch with 278m of vertical gain. This is a technical fell run starting from the Old Ross Road, initially following the Beacons Way through the atmospheric Pant-Skirrid Wood. The terrain is entirely off-road, transitioning from sheltered woodland tracks to a steep, grassy ascent that reaches the distinctive ridgeline. Runners will face a challenging "Grade 5" hilly profile, but the effort is rewarded with a fast, exhilarating descent back to the start after conquering the iconic peak.

Local runners affectionately call this hill "The Skirrid" (Ysgyryd Fawr), derived from the Welsh word 'Ysgryd,' meaning to shake or tremble. According to local folklore, the dramatic landslide on its western side occurred at the moment of the Crucifixion, earning it the name 'Holy Mountain.' As you run past the ruins of St Michael’s Chapel at the summit, take a moment to look across the Usk Valley—on a clear day, the views stretch from the Black Mountains all the way to the Bristol Channel, offering one of the most historic panoramas in Monmouthshire.