Just off the B3134 in Somerset is a portal to the underworld. The smaller of two openings to Goatchurch Cavern, it’s called the Tradesman’s Entrance – and through it I am squeezing. After tumbling on my bum over damp smooth rock, lacerating a jumpsuit in the process, I venture down and down, sometimes crawling, sometimes standing upright, trying to find footholds in the dark.
I’m here with film-maker Robert Petit, so he can show me something of what he’s been experiencing for the past five years, on his way to making an endearingly poetic documentary film called Underland, which riffs on nature-writer Robert Macfarlane’s bestselling 2019 subterranean travelogue of the same name. We’re heading 100ft underground to the Boulder Chamber where, over sugary snacks, I will quiz him about his obsession.
“Some fear is good,” says Petit as we travel downwards. But not too much. “Hyperventilating takes away the oxygen.” What if I freak out? Or twist my ankle? Or join Pleistocene mammoths and lions in the fossil record? I’m not yet terrified but I yearn to be on the cliffs above this perforated landscape with a mountain goat nibbling grass and looking with disdain on foolish humans below.
And yet many, including the three protagonists of Petit’s film, feel otherwise. The upside-down is where they feel, existentially, the right way up, free from the constraints of the surface world. One of them, urban explorer and geographer Bradley Garrett, who we see in the film savouring the faecal tang and abandoned car wrecks of Las Vegas’s storm drains, says that down there he experiences the smell he “most associates with freedom”.
Petit, too, feels free underground. “And not just because there’s no wifi,” he laughs. “Time changes down here – it thickens and slows.” True enough, but he has alerted Mendip Cave Rescue to send down a team if we don’t surface by 3.30pm so we’re not completely disconnected from normal clock time.
While I stumble and plummet, 41-year-old Petit bobs and weaves around me like a genial buttered otter, attaching ropes and hefting the Guardian photographer’s kit, shouting instructions that may save our lives. “Don’t go down the Coal Chute!” he says, nodding with his headtorch at some yawning abyss. “Stay away from Jacob’s Ladder!” Every feature down here has been morbidly named by sarcastic explorers, from Desolation Row to (my least favourite) Abandon Hope. “It’s like Alice in Wonderland,” says Petit. But I feel more like Winnie the Pooh, worried that I’ll get stuck between narrow rocks until rescuers pull me out.
