Map & Elevation
About this Route
Llyn Idwal sits inside one of Eryri’s most striking mountain bowls. From the Ogwen Centre, a mountain path leads into Cwm Idwal and around the lake beneath the Idwal Slabs and the dark cleft of Twll Du, the Devil’s Kitchen. The surrounding cliffs give the walk a mountain atmosphere while the route remains below the high passes and summits.
This GPX takes the lower clockwise circuit: approach the lake from Ogwen, follow its eastern side, cross the rough ground at the southern end and return along the western shore. It measures 4.5 km with 161 m ascent. Allow 2–3 hours for the uneven paths, views and stops; the 1h 10m Naismith estimate is moving time only. The route does not climb the Devil’s Kitchen or continue to Y Garn or the Glyderau.
The glacially shaped valley interested Charles Darwin, who returned in 1842 and recognised evidence of the ice that had once occupied the cwm. His description below refers to that clear geological story. The boulders, moraines and great hollow around the lake make the connection visible during the walk, without needing to venture onto the fragile slopes or climbing rocks.
Although relatively short, this is a mountain walk on rough, undulating ground. The approach climbs on rocky paths, and the circuit includes wet rock and stream crossings. Water levels, ice and strong wind can make the lower route difficult. Give grazing cattle room, keep dogs on leads and stay on established paths through the nature reserve. Enjoy the lake from the shore and help protect its sensitive habitat. Parking at Ogwen is limited, so consider the bus services and check current access and weather before travelling.
A house burnt down by fire did not tell its story more plainly than did this valley.
Charles Darwin, Naturalist, describing the glacial landscape of Cwm Idwal
Route Waypoints
Start beside the Ogwen Centre, near SH 649 603. Take the mountain path by the visitor centre, pass through the gate and cross the footbridge over Afon Idwal. Follow the established uphill path towards Cwm Idwal.
Follow the approach into the cwm and reach the northern end of Llyn Idwal. Take the clockwise circuit along the eastern side, with the lake on your right. Keep to the established path at the junctions; the Darwin boulders lie above this part of the lake approach.
Continue south beside the lake and through the wall opening. The path rises over rough moraine ground towards the Idwal Slabs area. Before the slabs, take the lower circuit to the right rather than climbing towards the high-level route.
Follow the rough lower path across the southern end of the cwm, using the established stream crossings. Keep below the steep paths towards the Devil’s Kitchen. Water can cover crossing stones after rain; turn back if you cannot cross safely.
Turn north on the western side of the lower circuit. Follow the path through the moraines, cross Afon Clyd on its footbridge and continue to the northern shore. Cross the outlet bridge to complete the lake circuit.
Rejoin the approach path and retrace it downhill to the Ogwen Centre. Take care on wet rock and steps, allowing space for people climbing towards the lake. Finish at the original trailhead beside the visitor centre.
Essential Tips
At the southern end, use the lower path before the Idwal Slabs and stay beneath the headwall. The Devil’s Kitchen ascent and high-level routes involve steeper, more demanding ground and are outside this walk.
Carry waterproofs, warm layers, a map and suitable footwear. Wet rock, ice, high streams and strong wind can affect this lower circuit. Turn back if a crossing or section of path is unsafe for your group.
Stay on established paths, give cattle space and keep dogs on leads. Avoid disturbing the fragile vegetation or leaving litter. Enjoy Llyn Idwal from the shore and follow the reserve’s request to keep out of the lake.
The Ogwen Centre has limited designated parking. Consider the bus services, checking current routes and timetables before travelling. Do not obstruct the A5, gateways or verges; follow local parking and access notices.
Frequently Asked Questions
How long is the Llyn Idwal circular walk?
This lower clockwise circuit from the Ogwen Centre is 4.5 km with 161 m ascent. Allow 2–3 hours with stops. The 1h 10m Naismith estimate is moving time and does not allow for the rough paths, photographs or difficult conditions.
Does this walk go up the Devil’s Kitchen?
No. It circles Llyn Idwal on the lower path beneath the cliffs. At the Idwal Slabs area, follow the lower circuit rather than continuing uphill towards the high-level route or the Devil’s Kitchen ascent.
Is Llyn Idwal an easy lakeside stroll?
It is a moderate mountain walk with rocky climbing on the approach, uneven paths and stream crossings around the lake. Wet weather, ice and strong winds can make it harder. Wear suitable footwear and turn back if the conditions exceed your group’s ability.