Castell Mawr, the conspicuous turret of limestone on the west side of Red Wharf Bay, has seen a lot of attention of late from a group of island based climbers, including Niel Blom, Ryan Gibson, Nathan Binstead, Lee Williams, Ian Lloyd-Jones, Phil Targett and Pete Robins.
The history of development is a little hazy, but it is known that Glenda Huxter bouldered here back in the Ď90s Ė Glenda recalls doing some grade 6 traversing but nothing in the grade seven bracket.
The main action is focussed around a small cave and book corner feature. There are numerous problems in the grade 5 - 6 range but the standout problem is the aptly named Flowstoned 6C. This tackles the obvious line on the left hand side of the crag. Start on lower side pulls to gain a pinch for your right and a side pull on the left, head upwards using smears and cool heel hook beta. Snatch for crimps and side pulls until it is possible to finish matched on a sloping flowstone jug 4ish metres up. Given its height, the likely first ascent of this goes to Neil Blom.
Pete Robins paid a visit and climbed a few new lines and links. Peteís Roof 7A starts on the sea/bay side of the through arch, sitting on the left side (if looking back in through the arch). Tack up the left wall/arete until you can reach a guppy thing on the right side. Then do a weird 180 degree leg spin to get on the right side of the arch. Move up/into the arch and traverse left around the back wall, heading for easy ground on a pillar.
Pete also did two traverses: firstly, a rightwards crossing of the right wall of the main area from a sds in the cave in the corner (this is 6C+/7A, but can be done at 6A - Herbertís Problem if started standing at the roof of the cave), and secondly, traverse both the left and right wall rightwards. This is easier (6C/+) as you miss out the sds in the cave (NB. this was probably first climbed by Glenda). The left wall on its own, and climbed right-to-left is Illinois Enema Bandit Traverse 6B+
Approach: from the car park near 'the boathouse' cafe walk leftwards across the bay towards obvious limestone turret, until you see a corroded muddy path on your left leading to the bouldering area.