Llyn Trawsfynydd
Llyn Trawsfynydd: A Reservoir of Natural Beauty and Heritage
Llyn Trawsfynydd is a large reservoir located in southern Snowdonia, near the village of Trawsfynydd. Spanning approximately 1,200 acres, it is one of the largest man-made lakes in Wales. Set against the rolling hills and rugged landscape of Gwynedd, Llyn Trawsfynydd is a unique blend of industrial heritage and natural beauty. Originally created to supply water for the Maentwrog hydroelectric power station, the lake later served as a cooling reservoir for the now-decommissioned Trawsfynydd nuclear power station. Today, it’s a popular destination for outdoor activities and wildlife spotting.
A Tranquil Escape in Southern Snowdonia
Llyn Trawsfynydd’s expansive waters are surrounded by tranquil moorland and low-lying hills, offering a peaceful retreat from the busier areas of Snowdonia. The lake’s size and diverse shoreline make it ideal for a range of activities, from kayaking and fishing to walking and cycling. The nearby village of Trawsfynydd provides a glimpse into local history and culture, while the lake itself is a haven for birdwatchers and anglers. Whether you’re here to explore the surrounding trails or simply relax by the water’s edge, Llyn Trawsfynydd offers a unique and peaceful experience.
© Brad Carr
Walks & Hikes Around Llyn Trawsfynydd
Llyn Trawsfynydd offers a mix of tranquil lakeside trails, historic points of interest, and gentle countryside walks, ideal for those looking to explore at a relaxed pace.
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Llyn Trawsfynydd Circular Trail
- 8 mi
- 3.5 hrs - 4.5 hrs
A scenic route around the entire lake, crossing the impressive footbridge and passing forests, moorland, and peaceful shoreline views.
Trawsfynydd to Tomen y Mur Fort
- 3.5 mi
- 1.5 hrs - 2.5 hrs
A rewarding walk from the village to the Roman fort of Tomen y Mur, with sweeping views of the lake and surrounding hills.
Lake View Short Loop (South Shore)
- 2.5 mi
- 1 hrs - 1.5 hrs
A shorter trail along the southern section of the lake, great for casual strolls and spotting wildlife by the water’s edge.
Coed y Rhiw Woodland Trail
- 2 mi
- 1 hrs
Crib Goch is an exposed, knife-edge ridge for confident scramblers, thrilling, technical, and not for the faint-hearted.
Rhyd y Sarn to Llyn Trawsfynydd Linear
- 4 mi
- 2 hrs
A gentle countryside walk that leads to the eastern banks of the lake, with views across the valley and the opportunity to connect with longer trails.
What to Know Before You Go
Due to the lake’s size and exposed location, weather conditions can change quickly, especially during the colder months. Dress appropriately and bring waterproof gear, particularly if planning a longer hike or bike ride. The lake’s water is cold year-round, so swimming is not recommended. Make sure to purchase a fishing permit if angling.
Why We Love Llyn Trawsfynydd
Llyn Trawsfynydd is a blend of the past and present, where industrial heritage meets natural tranquillity. The reservoir’s vast waters, framed by the rolling hills of southern Snowdonia, create a sense of space and calm that’s hard to find elsewhere. Whether you’re cycling around the lake, casting a line, or simply sitting by the shore watching the sun set, the peaceful atmosphere leaves a lasting impression. The juxtaposition of nature and history makes it a truly unique destination.
How to Get to Llyn Trawsfynydd
Llyn Trawsfynydd is located just off the A470 between Dolgellau and Porthmadog (postcode: LL41 4DT). Parking is available at the main visitor areas, with spaces near the village and at the start of the circular walk. Public transport options include buses from Blaenau Ffestiniog and Dolgellau that stop in Trawsfynydd village.
A Bit of Llyn Trawsfynydd History
The reservoir was created in the 1920s to support hydroelectric power generation and later became integral to the cooling process of Trawsfynydd nuclear power station, which operated from 1965 until 1991. Following the plant’s closure, the focus shifted to decommissioning and environmental restoration. Today, Llyn Trawsfynydd is a popular recreational area, showcasing how industrial landscapes can be repurposed for public enjoyment.
Keep exploring
Llyn Trawsfynydd is just one of Snowdonia’s captivating lakes. Ready to discover more? Check out our guides to nearby waters and scenic trails!