Cregennan Lakes and the Mawddach Trail loop from Barmouth

Embark on a challenging gravel biking adventure with the Cregennan Lakes and Mawddach Trail loop from Barmouth. This difficult route spans 24.8 miles (39.9 km) and features a significant 3247 feet (990 metres) of elevation gain, typically taking around 3 hours and 48 minutes to complete. You will experience a dramatic contrast between the flat, well-maintained Mawddach Trail, which follows an old railway line along the estuary, and the demanding climbs towards the beautiful Cregennan Lakes, nestled north of Cadair Idris. Expect varied terrain, from smooth gravel to rougher, unpaved sections with large holes and rocky parts as you ascend.

While the Mawddach Trail portion is accessible to all skill levels, the climb to Cregennan Lakes requires very good fitness. Some gradients can be steep, reaching up to 20% or even 30% in places, and you might encounter technical sections where pushing your bike is necessary. It is often recommended to cycle this loop clockwise, as the ascent to the lakes is more gradual in that direction. Make sure your tires are at least 700x40c to handle the rougher segments near the top.

This route is notable for its stunning scenery, offering panoramic views across the Mawddach Estuary, the picturesque Cregennan Lakes, and the grand Cadair Idris range. On a clear day, you can even see the mountains of Snowdonia and the sea from the lake summit. The Mawddach Trail itself has historical significance, following an old railway line and crossing the Barmouth Bridge, which is the longest timber viaduct in Wales. The Cregennan Lakes are owned by the National Trust and are free to visit.