Also known as The Lost Boulders of Atlantis, this is the venue that puts the lake in to 'Lakes Bouldering'. Perhaps it’s a shame that some of the most enjoyable mid-grade bouldering in the Lakes is underwater most of the year, but then again so is the best rock climbing, up on Scafell. The up-side is that being submerged in Thirlmere for 9 months a year makes these boulders, when they emerge, as clean and rough as you can hope for.