Coumshingaun Lake

Coumshingaun is a corrie - a hollow scooped by a glacier into the side of a mountain - and it is one of the most textbook examples in Europe: a near-circular basin with a lake in the bottom, enclosed on three sides by cliffs rising around three hundred metres, and open only to the east where the ice flowed out. The walk in from the car park takes about an hour on a rough boggy path and ends at the water with the wall of the coum above, which is the trip most people make. The other option is the horseshoe: a circuit around the rim over both arms, involving steep loose ascent, exposed scrambling on the northern arm and a real drop on the inside edge. It is a serious mountain route, badly underestimated, and rescue callouts here are frequent. Cloud on the rim removes all reference points.

What you actually see

• The corrie - a textbook glacial basin, cliffs on three sides.
• The lake - filling the floor of the hollow beneath the headwall.
• The horseshoe rim - the circuit over both arms, steep and exposed.
• The scale - around three hundred metres of cliff above the water.

When to go

May to September. The lake walk is manageable most of the year; the horseshoe needs settled clear weather. Cloud on the rim makes navigation genuinely dangerous.

Honest expectations

The lake path is rough and boggy despite the short distance. The horseshoe involves exposed scrambling above a long drop and is a frequent rescue callout - it is not a hillwalk. No facilities at the car park.

Nearby

Mahon Falls is south in the same range; the Copper Coast is on the shore.