Almost 200m above the magical Llyn Idwal National Nature Reserve are the mercury waters of Llyn Bochlwyd. For many, this small, isolated lake offers a welcome stopping point en route to the vertiginous heights of Tryfan – one of Snowdonia’s most prized summits.


But the pool has another secret: an unruly cascade that spills from its outflow between two huge rocky buttresses that conjure visions of Tolkien’s Gates of Argonath, or The Pillars of Kings.

Hiker on Tryfan looking towards Glyder Fawr and Llyn Bochlwyd in Snowdonia
The rugged mountain lake Llyn Bochlwyd can only be reached on foot Getty

A two-mile walk from Llyn Ogwen to the secluded waters of Lly Bochlwyd in Snowdonia National Park.

2 mile/3.2km | 1.5 hours | moderate

1. Over icy waters

From the National Trust’s Carneddau and Glyderau parking area, take the path to the left of the toilets. The way immediately veers left, climbing among heather on stone slabs for 50m to reach a wooden gate. Just beyond is the Afon Idwal, a vivacious river of split rock and steaming white water, spanned by a wooden bridge. Erected in 2010 to replace the old structure, the bridge is made of sessile oak sustainably harvested from the Plas Newydd parkland on the eastern shores of Anglesey. Beyond the falls is the sprawling mass of Y Garn, one of 15 peaks in Wales over 3,000ft in height.

Castell y Gwynt in Snowdonia

2. Path less travelled

Cross the flow and continue on the well-maintained path for 150m. Cwm Idwal is one of just a few places where the rare Snowdon beetle has been recorded, so keep your eyes peeled. Where the main track bends right, take the small side-trail to the left. The way becomes rougher underfoot yet remains clear as it ascends, with the distinctive scalene summit of Tryfan straight ahead.

Snowdon leaf beetle, or rainbow leaf beetle (Chrysomela cerealis)
also known as the rainbow leaf beetle due to its iridescent exterior, the Snowdon beetle was last recorded in the valley in 1980 Getty

After about 500m, the path steepens and bends to the right between two hulking buttresses: Clogwyn Y Tarn and Bochlwyd Buttress.

Stick to the right-hand side of the gap (Clogwyn Y Tarn) to meet Nant Bochlwyd. Do not cross the river but instead remain on the main trail. Climb a series of steps alongside the cascade, which gradually become more energetic, before flattening to a boulder field interwoven with mats of grass and plaited waterways.

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3. Lost llyn

Ahead is Llyn Bochlwyd, a placid lake hidden from the tourist trap of Llyn Idwal far below. Take some time to appreciate the grandeur of the water and the surrounding Glyderau mountains then return to your inbound route, dropping back into the gap.


As you emerge from between the buttresses, look for a way to cross the river on your right (if in spate, return the way you came). A permissive path heads north-east, descending over rock and grass for about 600m to the car park at Llyn Ogwen. Cross the road, turn left and follow the pavement for half a mile to complete the loop.

Nant Bochlwyd and Llyn Bochlwyd walking route and map

Nant Bochlwyd and Llyn Bochlwyd walking route and map


Daniel Graham of COuntryfile magazine on a hike with wet hair and blue coat and hills in background
Daniel GrahamOutdoors editor, BBC Countryfile Magazine

Danny is the outdoors editor of BBC Countryfile Magazine, responsible for commissioning, editing and writing articles that offer ideas and inspiration for exploring the UK countryside.