When Daniel Curley kills the torch as we reach the depths of “hell” the blackness is so total, the Dark Lord himself would struggle to find a way out.
In this enchanted cave, eyes never grow accustomed to the darkness and one would have to sympathise with the young men of times past sent down to dabble with demons for days as part of a terrifying teenage rite of passage.
The cave of Uaimh na gCat (Oweynagat) - or the cave of the cats or the gates of hell, take your pick - some three kilometres from the Roscommon town of Tulsk is reputedly the very spot where Samhain, and ultimately Halloween, was born.
For a place that plays such a pivotal role in ancient - and popular - cultures, it’s easy to miss. And almost impossible to find.
But despite its low-key entrance, this damp and muddy hole snaking 37 metres under a field often shrouded in pleasingly atmospheric fog was central to the people of Rathcroghan, Connacht’s pre-historic heart.
The cave is one of 240 sites stretching back 5,500 years in the area but on days like this it’s the one that attracts all the attention. Because it is on days like this, our ancestors believed, that the beasts would emerge from the other word, shepherded by the goddess Mórrígan, to shift the seasons from autumn to winter
As Dr Curley, the head of the Rathcrogan Visitor Centre, guides The Irish Times down an unpromising looking boreen with thick tufts of grass growing down the centre, he takes us on a whirlwind tour of ancient Ireland.
“This is the origin of Samhain,” the archaeologist says. “This is the place where creatures were imagined to emerge from the bowels of the earth to create the winter.
“Samhain is something we have stitched into ourselves and there’s no getting away from that. The Halloweenisation, that’s common with immigration to America, that’s its own business.
“Ireland 2,000 years ago was a vastly rural space and there were no towns, there were dispersed settlements but there were still opportunities for mass gatherings,” he says.
Those opportunities focused on St Bridget’s Day, Bealtaine, Lughnasa and Samhain.
“Rathcroghan is like an empty capital,” Dr Curley says. “The place would get lit with social engagement and then everyone would disperse.”
Much of the lighting on such days might have come from carved turnips, a tradition that brought us the pumpkin carving of today, and it was also common for those gathering to use disguises to hide from the demons knocking about.
“Those types of gatherings might sound abstract,” suggests Dr Curley. “But we’re still doing it today. Just look at the Electric Picnic, Glastonbury, Lollapalooza, these are all touchstones. Then you have the Puck Fair, the Ballinasloe Horse fair, climbing Croagh Patrick on Reek Sunday. We are doing these things without realising it.”
We reach a small metal gate which leads to a much older gate, almost hiding under a tree thought to have magical properties.
Oliver Cromwell wanted to send the Irish who displeased him to hell or to Connacht but it might have been more accurate had the arch-puritan suggested we go to hell and to Connacht as this, it appears, is the way in.
“This is the gate where the demons and beasts from the other world emerged,” Dr Curley says as he pulls on the heavy boots and waterproofs The Irish Times is sadly lacking.
Down on all fours we crawl though the hole into a mucky murk. Once through the gates there is a sharp left turn, and a stretch that would be impossible to navigate without artificial light, as the cave appears designed to deliberately kill the sun.
A few metres in and it is possible to stand.
Dr Curley says it is from here “the three-headed monsters, the flocks of birds with breath so foul they’d take the leaves off trees” came. “Then there was the giant wild boars, who’d wither every piece of vegetation they touched, the female werewolves, the giant cats and the otherworldly armies that would troop out of the other world from this portal to create a world that is ready for winter.”
Then he brightens. “It’s a bit of a hidden gem.”
Not more than 300 visitors will get access to Roscommon’s hell over the Halloween period as the visitor numbers are carefully managed by Dr Curley and his team.
“We don’t really want it to be that well known as we’re trying to balance things here. We have 60 farmers out there farming the land in a very sensitive and limited way because of the archaeological importance of the site.”
Of course, Rathcroghan is not the only place to stake a claim to being the home of Halloween and while the Gates of Hell have been keeping things low key, the Boyne Valley has been bouncing all weekend with the Púca festival celebrating its role in the birth of the big night.
The streets of Trim came alive on Saturday evening with great fires burning under the castle walls to a wild drummer’s intoxicating beat and beasts bellowing under the watchful eye of wolfhounds as part of an exuberant parade that snaked through the town as night fell.
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And on Tuesday night, it climaxes at the Fair Green in Athboy where ‘An Lasadh Suas’ (The Lighting) closing ceremony takes place.
It is all to recall how on Samhain Eve, in times long past, fires would be extinguished across Ireland only to be re-ignited from the flames burring at the nearby Hill of Ward.
If only those ancients - in Roscommon and in Meath - knew that one day their sacred rituals would see the children of Ireland - and many other parts of a world that they could not have imagined existing - wandering the streets dressed as Barbie, Ken, Taylor Swift and Oppenheimer (maybe?) while consuming vast quantities of sugar.