The nearer peak, Aran Benllyn, is at 884 m asl, whilst the second, Aran Fawddwy reaches 906 m. It's something like fifteen years since I was up there. Scary thought.

Bala Lake is a classic glacial ribbon lake, ~6½ km long by ~1½ km wide, making it the largest natural lake in Wales.
According to Welsh mythology recorded in the 6th Century 'Mabinogion', the lake was formed by supernatural flooding of the valley containing the hall of 'wild lord' Tegid Foel.
Irrespective of whether there's a Celtic palace on the lakebed, Llyn Tegid does accommodate the gwyniad, a unique subspecies of Coregonus lavaretus (a variety of salmon) presumably stranded here at the end of the last Ice Age. Populations are being artificially established in other nearby lakes, as that in Bala Lake is threatened by algae, climate change, and human activity, including the thoughtless introduction of another fish species.