Restricted Access

July 2018 - Major rockfall affects Lost World/Mordor areas. In recent years there have been significant and massive rockfalls (hundreds if not thousands of tons of rock)  in this area, and in early July another significant rockfall occured here, that would have wiped out anyone in this area at the time. There is further significant and unpredictable rockfall likley here and it would be prudent to avoid this area. 

The Upper Dinorwig quarries are mainly owned by First Hydro. Access for climbing or any access away from the designated footpaths is not permitted by the landowners, due to liability concerns. However it's rare for climbers to be asked to leave and in general it appears that if climbers keep a low profile, avoid damaging fences, do not interfere with any of the power station buildings or apparatus or any of the historic structures within the quarry that climbing is possible. Access to the whole of the upper quarries have become especially sensitive in recent years and climbers should not gather in large numbers, especially at Dali's Hole area. Bolts have been removed from Dali's Hole by a local climber (late 2010) who was concerned that continued use of this venue by large groups of climbers would jeopardise access to the whole site. There have also been a number of reported altercations between climbers and First Hydro security staff over the years at this venue.

BMC advice remains unchanged - the landowners do not give permission for public access (including for climbing) away from the public paths. Please do not damage fences or signs and if accosted by security staff, please be courteous and report any issues to the BMC.

Seasonal Restrictions

Reason: Nesting Birds

A fence has been errected across the base of the Dali's Hole area to deter access to this area due to liability concerns by First Hydro. Access to this area is especially sensitive at this time and security staff have been reported to be asking climbers to leave this area.

47m, 2 pitches.

Rockfax Description
An adventurous sport route. Start on a vegetated ledge by a tree.
1) 6b, 20m. Follow the line of bolts steeply up a line of cracks behind the tree. Belay on the ledge above.
2) 6b, 25m. Head left to the first bolt and follow the line of bolts to a groove. Make technical moves up this to a bolt belay below the top. Alternatively, top out and belay off the fence posts. © Rockfax

UKC Logbook Description
An adventurous multi pitch F6 in Twll Mawr! The route climbs the South Wall and is accessed from the right hand fork of the main access tunnel. Start on a vegetated ledge which has a Sycamore tree.
Pitch 1 (22m) - a line of bolts leads steeply with interest up the cracks behind the tree. Some high stepping moves and confident laybacking will hopefully gain the top of the wall and the start of the main slab. Belay bolts on ledge above.
Pitch 2 (25m) - traverse leftwards from the belay ledge to gain the first bolt, follow the line of bolts to a short but entertaining technical groove (crux). Continue to a bolt belay / abb point or alternatively continue up and over to top out and belay on the fence by the main quarry track.

NOTE: If you've enjoyed any of the bolted routes in Twll Mawr please consider donating to the North Wales Bolt Fund :-)

Pitch 1 Tesni Lloyd-Jones (aged14) Pitch 2 Celt Lloyd-Jones (aged 11) 18/Jun/2013.


Dinorwic Slate - Multi Pitch Sport Climbs , All the Llanberis SLATE sport @ 6b & 6b+ , Slate Sport , Twll Mawr Big Wall 1000 Metre Challenge! , Sl@teheads Sl@te , Slate Mastery , All multi-pitch sport routes (England and Wales) , North Wales To Do List


User Date Notes
BarwoodP 8 Aug, 2022 Show βeta
βeta: Nice route, good to brush up on multipitch climbing, loved the first pitch
Show beta
βeta: Nice route, good to brush up on multipitch climbing, loved the first pitch
Ian Ford 21 Jul, 2019 Show βeta
βeta: If topping out most of the fence posts are rotten. There is a larger sturdy one on the other side of the path. Probably best to just lower off.
Show beta
βeta: If topping out most of the fence posts are rotten. There is a larger sturdy one on the other side of the path. Probably best to just lower off.

Logged Ascents

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Guidebooks for Twll Mawr

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High 6b+
Mid 6b+
Low 6b+
High 6b
Mid 6b
Low 6b
High 6a+
Mid 6a+
Low 6a+
Votes cast 18
Votes cast 17
Style of Ascent
Alt Leads
Not Set
Flashed (β)
Not Set
Route of Interest
The Changeling

Grade: 6b ***
(Bryn Eglwys Quarry)

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