Llyn Idwal Circular Walk

Route overview

The walk begins at Cwm Idwal Visitor Centre and follows the mountain path beside Afon Idwal towards the lake. After reaching Llyn Idwal, the route completes a clockwise circuit of the nature reserve before returning along the same approach path.

What you will see

• The oak bridge over Afon Idwal
• Views towards Y Garn
• Darwin Idwal Boulders
• The shores of Llyn Idwal
• Idwal Slabs
• Twll Du, or Devil’s Kitchen
• Glacial moraines and protected upland vegetation
• The footbridges over Afon Clyd and Afon Idwal

This guide stays on the lower lakeside circuit. It does not include the rough high-level variation beneath the cliffs.

Follow the route

1. Visitor centre to the mountain gate

Begin beside Cwm Idwal Visitor Centre, next to the parking bays. Take the steps to the left of the building and follow the rising path for approximately 50 metres until you reach the mountain gate.

2. Cross the oak bridge

Pass through the gate and cross the oak bridge over Afon Idwal. Pause on or just beyond the bridge for a fine view towards Y Garn, with the river cutting through the foreground.

3. Follow the stone path to Llyn Idwal

Continue along the mountain path for roughly 500 metres until it divides. Take the right-hand fork and follow the more clearly surfaced stone path westwards for another 500 metres to the edge of Llyn Idwal.

4. Darwin Idwal Boulders

At the lake, begin the clockwise circuit by following the eastern shore. Before moving on, look uphill to the left of the path for a collection of large fractured rocks known as the Darwin Idwal Boulders.

The boulders were deposited by glacial action and were examined by Charles Darwin during his visit to Cwm Idwal in 1842. They are an early reminder that almost every part of this landscape carries evidence of ice.

5. Along the eastern shore

Follow the lakeside path south for approximately 500 metres until you reach a gate in the wall. The enclosed ground is protected from grazing so that native upland vegetation can recover.

Across the water, a small rocky island provides a glimpse of how parts of the cwm could look with less pressure from sheep and cattle.

6. Climb through the glacial moraines

Go through the gate and continue as the path rises gently over uneven mounds of rock and earth. These are moraines, material left behind when the glaciers retreated from Cwm Idwal thousands of years ago.

7. Idwal Slabs and the stream crossings

As the Idwal Slabs draw closer, stay with the lower lakeside route. Around 50 metres before the foot of the slabs, follow the path down to the right and use the stepping stones to cross the streams.

Important: the path continuing towards the cliffs forms part of a much rougher high-level option. It crosses steep and difficult mountain ground and is not included in this guide.

8. Beneath Devil’s Kitchen

Look up to the left for the immense headwall at the back of Cwm Idwal. The dark cleft in the cliffs is Twll Du, widely known as Devil’s Kitchen, a name often linked to the mist and vapour appearing to rise from the chasm.

Below it lies a vast scree and boulder field created by rockfall. The crags also support rare arctic-alpine plants, so remain on the established path and avoid disturbing the protected ground.

9. Rejoin beneath the boulder field

Continue climbing gradually until the lower trail meets the descending high-level path. Turn right and follow it into the heather-covered hummocks.

These formations are further glacial moraines. Fencing protects the peat and recovering vegetation from trampling and grazing; keep to the path through this sensitive section.

10. Afon Clyd and the north-west shore

The trail rises gently through the moraines and then descends towards the lake. Cross the footbridge over Afon Clyd and pass through the wall to reach the shingle shore on the north-western side of Llyn Idwal.

This is one of the best places to stop and take in the full scale of the cwm. The lake is a protected, nutrient-poor upland habitat containing sensitive plant life. Do not swim here, as this helps protect the water from disturbance and the spread of invasive species.

11. Complete the lake circuit

Follow the northern shore eastwards to a gate and the slate bridge over Afon Idwal. Cross the bridge to complete the circuit of Llyn Idwal, then retrace the approach path downhill to Cwm Idwal Visitor Centre.