Huelgoat and the Monts d'Arrée: The Rocking Stone and the Gates of Hell
Brittany, France
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Roche Tremblante Rocker
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250
XP
+100 France
= 350 total
2 days
Huelgoat and the Monts d'Arrée: The Rocking Stone and the Gates of Hell
250 + 100 XP
In the state forest of Huelgoat, 1,147 hectares on granite between 80 and 210 m, a river runs through a chaos of boulders and the Roche Tremblante, 137 tonnes, still rocks if you push it in the right place. To the west rise the Monts d'Arrée, Brittany's high moors, where the Youdig — a bottomless pool in the Yeun Elez peat bog — was held to be one of the gates of hell, and exorcists were said to shut demons into black dogs and throw them in. Most of the marsh has been under the Saint-Michel reservoir since 1937.
Required Activities
1
of 4
Walk the chaos along the Rivière d'Argent and work out what you are looking at: the granite rotted into rounded blocks underground, and Ice Age mudflows stripped the sand out from between them leaving only the sound stones. Then climb down into the Grotte du Diable, where the bandit Marion du Faouët once hid, and find the ten-metre gouffre said to be where King Gradlon's daughter threw her lovers, linked underground to the drowned city of Ys
2
of 4
Make the 137-tonne Roche Tremblante move — the trick is that its contact point is low, so push low and steadily rather than hard — then find the Ménage de la Vierge and the Mare aux Sangliers on the same path, and remember that quarrymen very nearly took the rocking stone away in the 19th century
3
of 4
Walk out to the Camp d'Artus and pace the line of its rampart: thirty hectares at first, then cut back to the northern part with the wall raised past four metres — a murus gallicus of interlaced beams pinned with iron, of the kind Caesar described, thrown up by the Osismii against Rome between 56 and 51 BC. The name is a later invention: the camp is centuries older than any Arthur
4
of 4
Climb the Roc'h Trévézel, 385 m of Devonian quartzite standing in beds tilted about 60 degrees, and look east and west along the line of roc'h — Roc'h ar Feunteun, Roc'h Trédudon, Roc'h Ruz, now reckoned the highest ground in Brittany — and notice they all finish at the same height, the last scraps of a flattened mountain range
Walk the chaos along the Rivière d'Argent and work out what you are looking at: the granite rotted into rounded blocks underground, and Ice Age mudflows stripped the sand out from between them leaving only the sound stones. Then climb down into the Grotte du Diable, where the bandit Marion du Faouët once hid, and find the ten-metre gouffre said to be where King Gradlon's daughter threw her lovers, linked underground to the drowned city of Ys
Make the 137-tonne Roche Tremblante move — the trick is that its contact point is low, so push low and steadily rather than hard — then find the Ménage de la Vierge and the Mare aux Sangliers on the same path, and remember that quarrymen very nearly took the rocking stone away in the 19th century
Walk out to the Camp d'Artus and pace the line of its rampart: thirty hectares at first, then cut back to the northern part with the wall raised past four metres — a murus gallicus of interlaced beams pinned with iron, of the kind Caesar described, thrown up by the Osismii against Rome between 56 and 51 BC. The name is a later invention: the camp is centuries older than any Arthur
Climb the Roc'h Trévézel, 385 m of Devonian quartzite standing in beds tilted about 60 degrees, and look east and west along the line of roc'h — Roc'h ar Feunteun, Roc'h Trédudon, Roc'h Ruz, now reckoned the highest ground in Brittany — and notice they all finish at the same height, the last scraps of a flattened mountain range
Before you go
The Huelgoat chaos is a scramble over wet granite with drops beside the path and no railings in places, so keep children in hand. Do not walk into the Yeun Elez bog: it is soft ground that has drowned sheep and shepherds, and the fog that sits on these moors makes it easy to lose the path. The Arrée moors burn badly and often — over 1,700 hectares went in three days in July 2022 — so respect any access ban and never light anything.
Storm Ciaran took 150,000 trees out of the Finistere state forests in November 2023 and Huelgoat was the worst hit on the GR 37; the Office national des forets has since reopened more than 95 per cent of the routes, but some paths were rerouted, so check the current state with the Huelgoat tourist office rather than an old map.
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Challenge Location
XP Breakdown
Challenge XP
250 XP
France country bonus
+100 XP
Potential total
350 XP
Country bonus earned on completion of your first challenge in France.
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