The Hellfire Club
An excavation in October 2016 found a Neolithic passage tomb under the ruined lodge on Montpelier Hill, dated between 3782 and 3377 BC. The man who built the lodge in the 1720s had quarried that tomb for its stone, which is where the story about the roof being torn off in a storm comes from.
Field Guide Entry
William Conolly, Speaker of the Irish House of Commons and reputedly the richest man in Ireland, put up a hunting lodge on the summit of Montpelier Hill around 1725. He took the stone from a cairn already standing there. When the roof came off in a storm not long afterward, the explanation that circulated locally was the devil, and the lodge was rebuilt with stone vaults instead. That is why the shell is still standing 300 years later.
The club that gave the hill its name came after the building. Richard Parsons, 1st Earl of Rosse, and the painter James Worsdale founded the Irish Hellfire Club around 1737, and Jonathan Swift described the membership as "a brace of Monsters, Blasphemers and Bacchanalians." What they did up here is a separate question. The black masses, the card game with a cloven-hoofed stranger, and the cat burned on the summit all come from accounts written long after the club had dissolved.
What was under the cairn
In October 2016 an excavation directed by Neil Jackman of Abarta Heritage, with volunteers from the UCD School of Archaeology, cut into the mound behind the lodge. It is a passage tomb. Radiocarbon dates from secure contexts run from 3782 to 3377 BC, and the dig recovered megalithic art, a polished stone axehead, worked flint, and what may be a mushroom-headed bone pin.
That puts roughly 5,000 years of building on one summit. It also means the retribution story has a real object underneath it. Conolly did take stone from a tomb.
What is there now
Coillte owns the hill. The ruin is unlocked, free, and open, a roofless shell of stone vaults covered in graffiti with the whole of Dublin laid out below it.
A trails upgrade began on January 9, 2026 and is scheduled to run 12 to 18 months, with an archaeologist and a project ecologist on the works. A visitor center for the Dublin Mountains survived a High Court challenge and a Supreme Court appeal dismissed in October 2022, and is in detailed design.
Visiting Information
Free, with a car park of about 70 spaces on the R115 at the foot of the hill, open 7am to 9pm from April through September and 8am to 5pm from October through March. The walk up is about 20 minutes on forest track and it climbs the whole way.
There is no lighting, no shelter, and nothing at the top except the ruin, which is a shell with open vaults and no barriers. The summit is exposed and the weather arrives fast.
Trail diversions are likely through 2026 and into 2027 while the upgrade runs, so the route may not match older maps. The Massy's Wood trail and the Dublin Mountains Way start from the same car park for anyone who wants more than the climb.
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