Route accounts give the height of Y Garn as 947 m. Its path starts from the same Ogwen car park as the Cwm Idwal walk.
The Walking Englishman, an independent route website, lists the circuit from Ogwen Cottage at 4.5 miles (7.2 km) and 2 to 3 hours.
The climb is steep rather than technical. Nearly Uphill, a walking website, reports no scrambling, only some rock steps and loose scree near the summit.
Starting at the Ogwen Centre
The Eryri National Park Authority, the body that runs the national park, names the start of its Cwm Idwal walk as the Canolfan Ogwen Centre. It is in Nant Ffrancon, at grid reference SH 649603.
The walk is on Ordnance Survey (OS) Explorer map OL17, according to The Walking Englishman. The Authority lists the same map for Cwm Idwal.
Parking in the Ogwen valley is extremely limited, says the Authority. Spaces fill up quickly in the spring and summer holidays.
The Authority lists paid parking at Ogwen, and the Ogwen Centre car park takes card payments only. Check its Ogwen visit page on the day for the current charges.
Never park on the double yellow lines along the A5. The Authority says this is not allowed at any time, on the road edge or the pavement.
Two buses are named on the Authority’s pages:
- T10: links Bangor, Bethesda and Betws y Coed, and stops at Llyn Ogwen. The trailhead is a minute’s walk from the stop.
- Bws Ogwen: a 9-seater electric bus from Bethesda to Llyn Ogwen.
If Ogwen is full, the Authority points to the buses from Bethesda. It also lists the car park at Bethesda Football Club, whose gate is closed from 22:00 to 07:00.
Up past Llyn Idwal
The path leads from the Ogwen Centre to Llyn Idwal, the lake in Cwm Idwal. Natural Resources Wales, the Welsh Government body for the environment, says the visitor centre stands next to the car park.
The first stretch is gentle.
The Walking Englishman records only 70 m of height gained by the time the path reaches the shore of the lake.
Y Garn lies inside a protected area. The National Trust, the conservation charity that owns the Carneddau and Glyderau estate, says the 398-hectare reserve includes the summits of Y Garn and Y Glyder Fawr.
The Trust asks visitors to enjoy the lakes from the shores. That includes Llyn Clyd and Llyn y Cwn, which lie higher up. It also lists no camping, no fires, no drones, and dogs on a lead.
The Pinnacle Crag path and its gradients
Above the lake the climb begins.
The Walking Englishman calls this line the Pinnacle Crag path. GPS Cycle and Walking Routes, a route-listing website, describes climbing towards Pinnacle Crag.
Nearly Uphill describes the same climb as the ridge to the right of Llyn Idwal.
The Authority lists the Cwm Idwal circuit at 5 km, 2 hours and 140 m of ascent. The Walking Englishman lists Y Garn at 626 m of climbing.
The Walking Englishman gives two measurements for the climb:
- over 200 m gained in half a kilometre, some of it at a 50% gradient
- on the summit ridge above it, 250 m in a kilometre of walking, a 25% gradient
Nearly Uphill says the route is steep in areas, with no scrambling. The Walking Englishman rates the whole walk as Hard.
Nearly Uphill allows 4 hours for the circuit, and says some people finish in 3.
Two ways round the circuit
Nearly Uphill prefers to climb the ridge right of Llyn Idwal first. The other way round, it says, leaves a long climb between Llyn y Cwn and the summit.
Nearly Uphill says both directions have steep sections. The Walking Englishman and GPS Cycle and Walking Routes both go up the ridge and come down by Devil’s Kitchen.
The Authority describes the route towards Twll Du, the Welsh name for Devil’s Kitchen, as challenging and steep. Parts of it cross loose rock and large boulders.
On the summit
Nearly Uphill, The Walking Englishman and GPS Cycle and Walking Routes all print the height as 947 m.
Nearly Uphill warns of loose scree as you approach the top. In thick cloud, it says, take extra care to stay on the path and not drift towards the edges.
Mountain conditions can change rapidly, says the National Trust. The Authority calls walking boots and waterproof layers essential.
Read the mountain forecast before you leave Ogwen, and plan to look at the sky again at Llyn Idwal.
The two ways back to Ogwen
From the summit, The Walking Englishman describes an even descent, at a 20% gradient over one kilometre, to the upland lake of Llyn y Cwn. Nearly Uphill says you turn left there for Devil’s Kitchen.
Below that turn, the accounts disagree.
The Walking Englishman found the path disappear into a boulder field, where it chose its own course. Nearly Uphill calls the path really good, with decent knees or poles.
The summit is where you choose your way back to Ogwen. There are two:
- Devil’s Kitchen, via Llyn y Cwn: this way crosses the loose rock and large boulders the Authority describes.
- The way you came up: this line has the 50% and 25% gradients above, so neither way down is easy.
For a day when you will not go up at all, the Authority describes a shorter, less challenging Cwm Idwal route that avoids Twll Du.
We compile and explain public route and safety information. We guide nobody and sell nothing on the hill.
Whichever way you come down, the path reaches Cwm Idwal and the Ogwen Centre where you started. The T10 stop at Llyn Ogwen is a minute’s walk from the trailhead.
