Llyn Idwal — 365 metres above sea level, in the perfect bowl of Cwm Idwal, surrounded by the crags of Y Garn, the Glyderau, and the Idwal Slabs — was Darwin's "site of desolate grandeur" and Wales's first National Nature Reserve. The lake itself is modest in size, but the setting is among the most dramatic of any mountain lake in Britain. This is Experience #22 of the Snowdonia 100.
The Setting
Cwm Idwal was carved by a glacier during the last ice age, the classic U-shaped valley and its lake both products of the ice that retreated around 10,000 years ago. The moraines deposited by that glacier are still clearly visible as low mounds at the valley mouth. The cliff face above the lake — the Devil's Kitchen and the Idwal Slabs — shows the characteristic smooth, striated rock surfaces produced by glacial action. Darwin recognised all of this in 1842 and was frustrated that his predecessors had not.
The Nature Reserve
| Designated | 1954 — Wales's first National Nature Reserve |
| Special features | Arctic-alpine flora, glacial geomorphology, breeding birds |
| Access | 5km circuit from Ogwen (Experience #12) |
| Warden | Natural Resources Wales |
The Legend
The lake's name derives from Idwal, a young prince who according to legend was drowned here by his foster-father Dunawt. The story goes that no bird will fly over the lake's surface — a claim enthusiastically made by Victorian guidebooks and equally enthusiastically disproved by observation. But the legend adds a layer of unease to an already atmospheric place, and on a grey autumn day, with mist on the crags above and the dark water below, it is easy to feel the force of it.
Experience #22 of 100 — Water and Light category.
Independently written — Snowdon.com