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Cwm Idwal & the Devil's Kitchen

Ogwen Valley, Wales

By The Alpines · Updated 2025-02-15 · 7 min read

5km
Distance (3.1 mi)
200m
Elevation Gain (656 ft)
1.5–2.5 hours
Duration
430m
Llyn Idwal outflow

Overview

Cwm Idwal is the most accessible mountain scenery in Snowdonia. In just a couple of hours and 5km of walking, you enter a glacial cwm surrounded by 600m cliffs, walk around a dark mountain lake, and stand beneath the Devil's Kitchen — a dramatic gash in the headwall where mist pours through the rock like steam.

The walk starts from the Ogwen Valley car park and follows a well-made path into the cwm. Llyn Idwal sits in a natural amphitheatre formed by the cliffs of Glyder Fawr, Y Garn, and the Idwal Slabs. The lake circuit is mostly on good paths with some rocky sections on the far side. The scenery is out of all proportion to the effort — you're surrounded by the same cliffs that mountaineers and rock climbers travel from across the UK to tackle.

Cwm Idwal was the first National Nature Reserve in Wales, designated in 1954 for its unique Arctic-Alpine plants that survived the last Ice Age in these shaded, north-facing cliffs. Charles Darwin studied the geology here and recognised the evidence of glaciation. It's a walk with layers — dramatic scenery, natural history, and geological interest all packed into a short circuit.

Highlights

  • Walk into one of Snowdonia's most dramatic glacial cwms
  • Circle Llyn Idwal beneath 600m cliffs — one of the most photographed scenes in Wales
  • Peer into the Devil's Kitchen (Twll Du) — a dark cleft in the headwall where mist rises from the rock
  • See Arctic-Alpine plants that have survived since the last Ice Age
  • A gateway walk — stand beneath the Idwal Slabs and the Glyderau ridgeline

What to Expect

Ogwen to Llyn Idwal

1.5km120m gain20–30 minutes

From the Ogwen Valley car park (by the A5), a well-maintained stone path climbs gently into the cwm. Within 20 minutes the landscape transforms — the road noise fades and the cliffs close in around you. Llyn Idwal appears below, dark and still, ringed by scree and rock. The Idwal Slabs — a famous rock climbing venue — rise steeply to the left.

Llyn Idwal Circuit

2km80m gain/loss45–60 minutes

Follow the path around the lake. The eastern (left) shore is the easier path on stone slabs. At the head of the cwm, the Devil's Kitchen comes into view — a vertical cleft in the cliff where water seeps and mist gathers. The return along the western shore is rougher, with some boulder-hopping and rocky sections that require care when wet. The full circuit brings you back to the outflow and the path down to the car park.

Best Time to Go

Cwm Idwal is walkable year-round and impressive in every season. Winter is arguably the most dramatic — the cliffs can hold ice and snow, and the Devil's Kitchen steams in cold air. The cwm is quiet and atmospheric in winter, though the western shore path can be icy.

Spring brings Arctic-Alpine flowers to the cliff ledges. Summer is busy — the car park fills early on weekends and bank holidays. Autumn is excellent, with quieter paths and moody skies that suit the landscape. Cloudy days are actually better here than clear ones — the mist in the Devil's Kitchen and the brooding cliffs are most dramatic when the weather is atmospheric.

What to Pack

Clothing

  • -Waterproof jacket and trousers (the cwm funnels wind and rain)
  • -Warm layer — the cliffs shade the cwm and it's cooler than the valley
  • -Walking trousers (the western shore can be rough on bare legs)

Footwear

  • -Walking boots with ankle support and good grip
  • -The western shore has wet, rocky sections — sturdy footwear matters here

Essentials

  • -Water and a snack
  • -Phone with offline map
  • -Camera — the scenery is extraordinary

Pro Tips

  • The Ogwen Valley car park (Ogwen Cottage) charges for parking — bring change or use the app
  • Walk the circuit anticlockwise (left shore first) for the easier path on the outward leg
  • The western shore is rougher — take care on wet rock, especially with children
  • This is a great walk to pair with a climb up Y Garn or the Glyderau if you want to extend
  • Visit the Ogwen Valley snack bar after for a brew — a Snowdonia institution

Physical Demands

A short, gentle walk with one rougher section. The path into the cwm is excellent. The western shore of the lake involves some boulder-hopping that requires sure-footedness. Overall, this is one of the easiest mountain walks in Snowdonia.

Gentle Ascent

moderate

120m of easy climbing on a well-made stone path into the cwm

Rocky Lake Shore

moderate

The western shore of Llyn Idwal has boulders and wet rock — requires careful foot placement

Are you ready?

You're ready for this adventure when you can:

  • Comfortable walking for 1.5–2 hours on paths
  • Can pick your way across rocky ground without difficulty

Frequently Asked Questions

Is Cwm Idwal suitable for beginners?
Yes — it's one of the best beginner mountain walks in Snowdonia. The path in and the eastern shore are excellent. The western shore is rougher but manageable with care. You get genuinely dramatic mountain scenery for very little effort.
Can I take children to Cwm Idwal?
Yes. The walk to the lake and along the eastern shore is fine for children who are steady on their feet. The western shore needs supervision as the rocks can be slippery. Many families walk to the lake and back without doing the full circuit.
Where do I park for Cwm Idwal?
The Ogwen Valley car park (next to Ogwen Cottage on the A5) is the starting point. It gets very busy on weekends and bank holidays — arrive before 9am in summer. The Snowdon Sherpa bus also stops at Ogwen.
What is the Devil's Kitchen?
Twll Du (the Devil's Kitchen) is a dramatic vertical cleft in the cliff headwall at the back of Cwm Idwal. Water seeps through the rock and in cool conditions, mist rises from the gap giving it its name. You can see it clearly from the lake path — the more adventurous can scramble closer on the approach to the Glyderau.

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Last updated: 2025-02-15 · 7 min read