Llyn Idwal

Llyn Idwal is a mountain lake in Snowdonia National Park in north Wales, lying in a pronounced glacial cirque below the Glyderau. It is notable for its rock faces and alpine-style scenery.

The site offers a short, accessible walk around the shoreline and immediate slopes, with obvious routes up the nearby slabs used by rock climbers and boulderers. The landscape is compact but dramatic, with steep cliffs rising directly from the water and clear views across the Ogwen Valley.

The lake and surrounding cwm were carved by Ice Age glaciation; the corrie and steep rock faces are classic examples of glacial geomorphology in Wales. The area has long been used for hillwalking and climbing, with climbing activity established from the late 19th and early 20th centuries.

Llyn Idwal sits above the Ogwen Valley, reached from the A5 and accessed on foot from Ogwen Cottage. The nearest settlements are small villages in the Gwynedd area of northwest Wales, and the site is inside Snowdonia National Park.

• Access: Short, well-waymarked paths start close to a roadside car park and provide an easy circular walk suitable for most visitors.
• Why go: The lake lies within Snowdonia National Park and is noted for its exposed rock faces that attract climbers and geology interest.

What to See #

• Cwm Idwal: Sits within a glacial hollow beneath steep crags and slabs that form the central features for walkers and climbers.
• Idwal Slabs: A series of smooth, near-vertical rock faces popular with trad climbers and boulderers, located on the lake's northern side.
• Ogwen Cottage: A longstanding outdoor base close to the lake that serves as a common start point for the circular walk and climbs.