Llyn Efyrnwy / Lake Vyrnwy to Llyn Tegid / Bala Lake high pass loop — Eryri / Snowdonia National Park

Embark on a challenging touring bicycle loop from Llyn Efyrnwy / Lake Vyrnwy to Llyn Tegid / Bala Lake, traversing the high passes of Eryri / Snowdonia National Park. This difficult route spans 34.4 miles (55.4 km) and features a substantial elevation gain of 3059 feet (932 metres), requiring very good fitness and typically taking around 3 hours and 45 minutes to complete. You will cycle through dense woodlands, open moorland, and past the expansive reservoir of Lake Vyrnwy, experiencing a landscape of mountains, valleys, and tranquil countryside.

While largely on paved surfaces, be prepared for some unpaved sections where you might need to push your bike. The route includes demanding climbs into the surrounding hills, notably the Hirnant Pass and Bwlch y Groes, which is the highest road pass in Wales. Expect very steep roads and descents, especially near Lake Vyrnwy and Rhiwargor. This loop is best enjoyed during daylight hours when the weather is clear, allowing you to fully appreciate the panoramic views across the Welsh landscape.

This trail is notable for connecting two iconic Welsh lakes via a high mountain pass, offering a true sense of frontier wildness and raw natural beauty. Bwlch y Groes, reaching 1800 feet (546 metres), is not only a challenging climb but also historically significant as a pilgrim route. You will also pass the impressive dam and distinctive straining tower of Lake Vyrnwy, and experience the charming, Welsh-speaking town of Bala by Llyn Tegid, Wales's largest natural lake.