Llyn Cau sits in the high cwm below the summit of Cadair Idris, enclosed on three sides by cliffs and ridges in a glacial bowl so perfectly formed it seems designed. The lake is dark, deep, and in certain lights, almost black — the cliffs above it streaked with moisture, the water reflecting only the sky and the rock. It is one of the most dramatic cirque lakes in Wales. This is Experience #30 of the Snowdonia 100, the last of the Water and Light category.
Getting There
| Start | Minffordd car park (Tal-y-llyn) |
| Distance to lake | 3.5km each way |
| Ascent | 450m |
| Time | 2–3 hours return to lake (not summit) |
The Minffordd Path climbs through the Nant Cadair valley into the cwm above. The lake appears suddenly as the path crests the rim of the bowl — the full scale of the cliff enclosure visible all at once. On the ascent you hear the stream draining from it; then the rim, and the dark water below, and the 250-metre cliffs of the south face of Penygadair above.
The Atmosphere
Llyn Cau carries a weight of legend disproportionate to its modest size. Old stories name it as bottomless, as home to a water monster, as the lake where Idris the giant bathed. None of these claims are true, but the setting generates them naturally: the enclosed bowl, the dark water, the cliffs that cut the sky into a rough circle above. Even in summer sunshine the lake is cold and the atmosphere palpably different from the open ridges above.
Experience #30 of 100 — Water and Light category.
Independently written — Snowdon.com