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.


Rockfax Description
A narrow and reasonably sound dolerite pillar between Scorpion and Bonza Crack gives a long and excellent and well-bolted sport route with good positions and interesting climbing. © Rockfax

UKC Logbook Description
A narrow and reasonably sound dolerite pillar running about half way up the N Wall of Twll Mawr between Scorpion and Bonza Crack gives an excellent and well-bolted sport route with good positions and interesting climbing.

Enter Twll Mawr via the tunnel and head diagonally up the scree slope to a flat area below the pillar just below where the scree rears up into jumbled blocks.

Scramble to the pillar base and climb its R rib to ledges, initially using the groove to the R. After this mediocre start a brilliant crux sequence leads up then L on layaways, crimps, occasional finger jugs and small footholds to an exposed resting position. Continue up the middle section more easily but still with interest then tackle the headwall with increased difficulty and excellent climbing to the top of the pillar (several possible lines most needing some faith in what will turn up). An excellent addition to the the options available in Twll Mawr. A 60 m rope just gets you down but be careful. A 70 does it comfortably.

H. Walmsley, I. Lloyd-Jones 25/Aug/2016.


Twll Mawr Big Wall 1000 Metre Challenge! , All the Llanberis SLATE sport @ 6c & 6c+


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Guidebooks for Twll Mawr

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High 6c+
Mid 6c+
Low 6c+
High 6c
Mid 6c
Low 6c
High 6b+
Mid 6b+
Low 6b+
Votes cast 7
Votes cast 7
Style of Ascent
Not Set
Route of Interest
G'Day Arete

Grade: 6c ***

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