Cwm Idwal walk
This walk offers some of the most dramatic mountainous scenery in the UK at the oldest National Nature Reserve in Wales.
Admire spectacular mountain views
It takes you into a normally inaccessible upland environment, and through beautiful ice-sculpted Cwm Idwal – a bowl-shaped hollow filled with the crystal clear waters of Llyn Idwal. The site is world famous for its rock formations and its rare and fragile plant life.
Ogwen car park, grid ref: SH648604
From the car park, walk to the east of the wardens hut and follow the footpath around the building. The footpath ascends steeply at times for approximately 56yd (50m) through verges of heather, towards the mountain gate.
Continue through the gate and over the oak bridge. The oak bridge was replaced in the summer of 2010 using sessile oak sustainably harvested from the nearby National Trust place at Plas Newydd. The bridge provides an excellent opportunity to photograph the peak of Y Garn, with Afon Idwal in the foreground.
The footpath meanders in a south-eastern direction for 550yd (500m) before arriving at a junction. Take the right fork towards the west along the more formal stone-surfaced path, and follow for another 550yd (500m) to the lake.
At Llyn Idwal (lake) you may choose a clockwise or anti-clockwise route around the nature reserve. This guide takes you on the clockwise option. Before setting off along the eastern lake shore, look left, a few yards above the footpath. Here you'll see a collection of large fractured rocks known as Darwin Idwal Boulders.
Darwin Idwal Boulders
Known as the Darwin Idwal Boulders, these rocks were originally deposited through a glacier crevice, and were first noted by Charles Darwin during his field visit to Cwm Idwal in June 1842.
The footpath follows the lake shore towards the south for 550yd (500m), until you arrive at a gate through a wall. The wall is there to exclude grazing animals from the nature reserve and to allow the regeneration of natural upland vegetation. Opposite the wall is a small island of rock in the lake. The vegetation growing there gives us a glimpse of how the Cwm may appear in years to come, without the grazing pressure of sheep and cattle.
Once through the gate the path begins to rise gently as you climb over mounds of rock debris (moraines) left behind as glaciers retreated from the cwm around 10,000 years ago.
You are now approaching the famous Idwal Slabs, a training ground for many pioneering mountaineers including Everest conqueror Edmund Hillary and his Welsh team mate Charles Evans. Roughly 55yd (50m) before the base of Idwal Slabs, follow the path down right towards a level area, using the stepping stones to cross streams. NB: An alternative high level route may be taken at this junction by following the path towards Idwal Slabs and up towards the base of the cliffs above. This route should only be attempted by competent hill-walkers as it involves very rough, steep ground and a difficult stream crossing.
Look up to your left and you'll see the sheer cliffs which form the headwall of Cwm Idwal, known as 'The Devil's Kitchen'.
The Devil's Kitchen
The headwall of Cwm Idwal earns its name from the mist which rises up through the dark chasm at the centre of the cliff face. Beneath the cliff lies a boulder field with dozens of gigantic individual rocks that fell from the face of the Devil's Kitchen, forming a scree. The cliffs above are composed of a more basic rock, and support a host of rare and fragile flora, including Arctic-Alpine plants. These include the Snowdon Lily, Mountain Avens, and many members of the saxifrage family.
The path rises gradually until you reach the junction of the high level route as it descends through the boulder field. Take a right turn onto this path and walk into an area of heather-clad hummocks.
The path climbs gradually through the moraines before descending gently towards the lake shore. Once across the footbridge over Afon Clyd, which tumbles steeply from a hanging valley to your left, go though the gate in the wall. You're now on a shingle beach on the north-west shore of Llyn Idwal. Take a moment to look to the back of the Cwm and absorb the scale of this natural amphitheatre. Try to imagine the area lying beneath a blanket of ice hundreds of metres thick, a mere hundred centuries ago.
The heather-clad hummocks found here are evidence of glacial moraines, deposited as the ice retreated up the Cwm around 10,000 years ago. The area between the footpath and the lake remains fenced off to deter both grazing by livestock, and erosion of the peat bog by people. You can see the effect of grazing by comparing the density of vegetation on both sides of the fence.
Follow the lake shore around to the east, until you arrive at a gate through a wall, leading to a slate bridge that crosses Afon Idwal as it drains out of the lake. Once across, you'll have completed the circular walk around the lake and can retrace your steps to the car park at Ogwen.
Ogwen car park and refreshment kiosk, grid ref: SH648604
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