9k Run Trefechan: Scenic Loop by Pontsticill Reservoir

Route Overview & Local Insights

Starting from Trefechan near Cefn-coed-y-cymmer, this 9.1km out-and-back route offers a steady, rewarding climb along a fully paved section of the iconic Taff Trail. With 81m of ascent, the incline is manageable but persistent on the way out, making it an excellent session for building sustained aerobic power. Runners will enjoy a smooth, high-quality surface that is perfect for tempo efforts or a scenic long run, culminating in the breathtaking views of the Pontsticill Reservoir and the southern peaks of the Bannau Brycheiniog (Brecon Beacons) before a fast, gravity-assisted return leg.

This stretch of the Taff Trail is steeped in industrial heritage, following the former route of the Brecon and Merthyr Railway. As you run, you’ll pass near the impressive Cefn Coed Viaduct, the third largest in Wales, which once transported coal and passengers across the valley. The area serves as a gateway to the wilderness of the national park, transitioning from the historic terraced landscapes of the South Wales Valleys into the tranquil, forested surroundings of the Taf Fechan valley. It is a favorite local haunt for those looking to escape the traffic and immerse themselves in the rugged beauty of the Welsh heartland.