The trail was originally constructed as the Marin Trail before being rebranded as Gwydir Mawr and Bach to reflect its dual-loop structure.
The route encompasses over 25 kilometers of mountain bike-specific trails, with the 'Mawr' loop covering 25km and the 'Bach' loop serving as a shorter 10km circuit.
Natural water drainage is a primary design feature, allowing the trail to remain rideable during high-rainfall periods common to North Wales.
The elevation gain is substantial, with the full Mawr loop totaling approximately 900 meters of vertical climbing.
The trails pass through historic coniferous plantation land that was once part of the Gwydir Estate.
Gwydir Mawr and Bach, formerly known as the Marin Trail, is a premier mountain biking destination located in the Gwydir Forest Park near Betws-y-Coed. The site features two distinct, purpose-built loops known as Gwydir Mawr and Gwydir Bach, which utilize the rugged terrain of Snowdonia. The route is characterized by high-altitude singletrack that winds through forest paths, offering elevated views of the Carneddau and Glyderau mountain ranges. The trails are categorized as red-grade, demanding intermediate to advanced technical bike-handling skills due to the rocky, rooty, and uneven natural forest floor. The course is famously physically demanding, featuring significant climbing segments that reward riders with technical downhill sections.
The high ridge section on the Mawr loop offering panoramic views over the Lledr Valley.
Ensure your mountain bike is fitted with high-grip tires, as the slate-based Welsh terrain can become exceptionally slippery when wet.
Bring a basic toolkit and spare inner tubes, as the remote sections of the trail are far from immediate mechanical support.
Check the Natural Resources Wales website for real-time trail closures due to forestry work before traveling.
Attempting the full Mawr loop without proper physical conditioning or a well-maintained mountain bike.
Trails may close periodically for scheduled timber harvesting operations; check the forest status map before arrival.
Cyclists should yield to pedestrians, keep to the marked trail to prevent erosion, and carry out all waste.
