Castle Gully

Page Type
Snowdonia, Wales, Europe
Route Type:
Ice Climbing
Time Required:
Half a day
Scottish Grade II/III
Number of Pitches:

Route Quality: 1 Votes

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Castle Gully
Created On: Dec 6, 2010
Last Edited On: Jan 15, 2015


Cwm Idwal and its centrepiece, Clogwyn y Geifr, is a popular spot in winter, its northerly aspect, high altitude and abundant moisture make it an ideal place for ice-climbing, and so, the ice climbers come. On a favourable weekend therefore, the Cwm’s crags teem with parties making their way from one ice fall to the next; searching, stopping, queuing, and eventually, if the cold hasn’t driven them back to their cars, climbing. So what to do if you don’t want to spend, what will inevitably feel like an unreasonable length of time, queuing? Well, for a start you could look elsewhere for your ice, there’re plenty of other viable winter venues in the area, or alternatively, you could look to one of the more inaccessible parts of the Cwm, the parts that most see as being too much effort to bother with. The cliff on the south-east side of Y Garn, which overlooks the aforementioned Clogwyn y Geifr, is called Castell y Geifr, and in Idwal terms, it’s as inaccessible as they come.

The cliff has a prominent straight gash running through its centre, this gives two routes, The Trench (Grade I) and Castle Gully (Grade II/III). The Trench is very straight forward and is probably better suited as a descent than an ascent, in fact it would make a fine ski run should the right conditions prevail; so for those in serious want of a quiet climb, this leaves Castle Gully, the subject of this page. Three pitches long, with an icy crux on its second pitch, it’s nowhere near the best the Cwm has to offer, but it isn’t entirely without charm and can provide a few hours of reasonable climbing. Furthermore, its altitude means that it is often in condition when other areas are more marginal.

Traditionally there has been no culture of claiming the first ascents of winter routes in Snowdonia, so unfortunately, the identities of the first ascentionists of this route are unknown.

Getting There

Castle GullyApproaching the gully
(Photo by Nanuls)
Castle GullyStarting Pitch 2
(Photo by Nanuls)
Castle GullyPitch 2
(Photo by Nanuls)

Castle Gully

Conveniently, Cwm Idwal and Castell y Geifr are located quite close to the A5, meaning that while the approach may be steep and arduous, at least it isn’t very long.

There is plenty of parking along the A5 near Ogwen Cottage (SH 648 603), some of which you have to pay for, some of which you don't. My advice is to never bother with the official car parks and just park along the roadside. There is a wide 'pavement' type verge on the southern side of the road that can easily accommodate the width of a car or minibus, and is completely free and never full (even on bank holidays). It also allows you to park even closer to the base of the mountain and the start of the path.

Take the path from the Cottage to Llyn Idwal (SH 645 595). At the northern end of the lake, bear right and follow its northern and western shore for about a kilometre. Leave the path at around SH SH 642 592 to begin climbing the snow covered heather and scree east facing slope towards the now obvious break. Enter the break and follow it to the steeper ice-filled gully that branches off right from The Trench. This is the start of the route (see photo ).

Route Description

A steeper ice-filled gully branches off right from The Trench. It is reasonably easy if it contains plenty of snow, but in normal conditions the second pitch is satisfyingly icy and challenging for the grade.

Pitch 1 (Tech. Grade 1/2; 40m): A rib splits the gully. Ascend either side of the rib at the same grade and belay on a commodious ledge just below the steep ice pitch.

Pitch 2 (Tech. Grade 3; 25m): A clear, narrow and increasingly steep ice filled gully is now ahead of you. The steep wall on the right will offer some rock protection while the ice in the gully will take a variety of ice screws. Climb this ice over bulges to easier ground above. Belay in snow or on the wall on the right.

Pitch 3 (Tech. Grade 1; 55m): Continue through snow and intermittent ice to the top, either cutting left to join The Trench or straight up the ridge above.

Essential Gear

In most conditions, it’s unlikely that many will see the need to climb pitches 1 and 3 as a leader and second and will therefore only need to consider gear for pitch 2. Ice tools, rigid crampons and a helmet are of course a necessity and double ropes may be more favourable than a single one as it reduces the risk of rope drag. A small rack of nuts and hexes will be useful and ice screws are essential if the crux is to be protected. This being Wales, short to medium length screws will be most useful. A Deadman snow anchor or equivalent may also be useful for constructing snow belays should they prove necessary.

Nant Ffrancon with Pen yr Ole Wen on the left and Tryfan on the right
(Photo by Nanuls)


Open Space Web-Map builder Code
Navigation Maps

OS 1:25k Explorer Series OL 17 Snowdon/Yr Wyddfa

OS 1:50k Landranger Series 115 Snowdon/Yr Wyddfa

Harvey Map Services 1:25k: Snowdonia North: Snowdon, Glyders, Carnedds

Harvey Map Services/BMC 1: 40k British Mountain Map: Snowdonia North

Road Maps

OS Travel Map 10 Wales/Cymru & West Midlands


Snowdonia (Official National Park Guide) Snowdonia (Official National Park Guide) by Merfyn Williams with contributions from Ian Mercer and Jeremy Moore

A handy book full of useful information and interesting facts about the National Park.
Welsh Winter Climbs Cicerone Guide: Welsh Winter Climbs by Malcom Campbell and Andy Newton

The only dedicated winter climbing guide to Wales. A bit dated now but nevertheless still relevant. The only problem is finding the right conditions.
Welsh Winter Climbs Wetpaint Guide: Welsh Winter Climbs – Clogwyn y Geifr PDF

Not a guidebook in the traditional sense; the contributors to the Welsh Winter Climbs ‘Wiki’ recognise that the Cicerone guide is unlikely to be updated anytime soon, and that in the interim period, something needs to cover the developments that have taken place since its publication. Plus it’s free!

External Links

Castle GullyThe approach to Castle Gully (Photo by Nanuls)
Castle GullyPitch 2 of Castle Gully (Photo by Nanuls)
Y GarnY Garn (Photo by Nanuls)

Government Bodies and Official Organisations

Snowdonia National Park Authority

Council for National Parks

Association of National Park Authorities

Natural Resources Wales


Royal Commission on Ancient & Historical Monuments in Wales

Gwynedd Archaeological Trust

Snowdonia Society

The National Trust

Hiking, Climbing and Mountaineering Organisations and Companies

British Mountaineering Council

The Climbers’ Club


Plas y Brenin National Mountain Centre

Hightreck Snowdonia


Mountain Weather Wales

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BBC Weather

Tourist Information

Visit Wales

North Wales Tourism Partnership

Local Information from

Local Information from Snowdonia Wales Net

North Wales Index


Welsh Public Transport Information

UK Train Timetable


Youth Hostel Association in Wales

Pete's Eats

Pen-y-Gwryd Hotel

Maps and Guidebooks

Ordnance Survey

Harvey Map Services

Cicerone Guidebooks

Climbers’ Club Guidebooks


North Wales Bouldering

Cordee Travel and Adventure Sports Bookshop

Wildlife and Conservation

Joint Nature Conservation Committee

Natur Gwynedd

North Wales Wildlife Trust

Royal Society for the Protection of Birds

Castle Gully

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