Llyn Idwal

Llyn Idwal is a small lake in Cwm Idwal, set among the Glyderau mountains in Snowdonia. It measures roughly 800 metres by 300 metres and lies within Gwynedd, though its eastern edge marks the border with Conwy County. The lake takes its name from Prince Idwal Foel, grandson of Rhodri Mawr, a ninth-century king of Wales. Welsh tradition tells of his death by drowning in the lake, though historical records say he fell in battle against the Saxons in 942. Another account claims he was cremated beside the water, following Celtic burial customs. The lake is fed by several small streams from the cwm and drains into the Afon Ogwen near Ogwen Cottage. Its waters are relatively poor in nutrients, a condition known as oligotrophic. A stone-paved path of 900 metres leads from the A5 road to the lake, while another route circles its shores. Two further paths climb steeply from opposite sides to reach the ridge near Twll Du, the Devil’s Kitchen, before continuing to Glyder Fach and Glyder Fawr. Visitors find a pebble beach at the north-west corner, sometimes used for quiet recreation. Swimming is not permitted, as the lake is a protected site supporting rare species. The surrounding cwm offers dramatic cliffs and ridges, with views across Snowdonia’s high peaks. Ogwen Cottage stands nearby, serving as a starting point for many walks. The contrast between the still water and rugged slopes makes the place striking.