Huelgoat Forest

The Chaos de Huelgoat is a jumble of granite blocks, many several metres across, heaped along a valley where the Riviere d'Argent disappears beneath them and can be heard running under the rock. The boulders are corestones, rounded by chemical weathering underground before the softer material around them eroded away, leaving them stacked. Paths thread between and over them past named features: the Trembling Rock, a block of around a hundred tonnes that can be rocked by hand at the right point, the Devil's Grotto reached down a ladder, and the Virgin's Camp. Arthurian and Breton legends attach to the whole wood.

What you actually see

• The boulder chaos - house-sized granite blocks heaped along the valley.
• The buried river - water heard running beneath the rocks.
• The Trembling Rock - a hundred-tonne block that moves at one point.
• The Devil's Grotto - a chamber under the boulders reached by ladder.

When to go

April to October; the paths are slippery and the rocks treacherous when wet, which in Brittany is often. Autumn colour suits the wood. Mist adds to it and reduces safety.

Honest expectations

Rocks are slippery and several paths involve scrambling; falls are common. The Trembling Rock only moves if pushed at exactly the right spot. Signage is limited.

Nearby

The Monts d'Arree lie west; Carhaix is south.