With a wicked glint in his eye he replied: “Yeah, that’s the hardest it’s going to get.”

If we’d known what he knew, perhaps we would’ve run for the hills. But we’d already signed up for the gorge walk and, as the three-course organic breakfast rumbled in my belly, it dawned on me — there was no turning back.

We continued to climb, shimmy, scramble, jump and roll our way through the river beds of the Neath Valley in the western part of Brecon Beacons National Park.

Covering 1347 sq km of south Wales, the park is a blanket of rolling hills and tumbling limestone and sandstone valleys. We were in the Vale of Neath, Pontneddfechan — an area trodden by Romans, romanticised by the painter JMW Turner and industrialised by coal mining, the remnants of which we passed along the Powder Trail following an old tram route through a tree-lined landscape of caves and cascading waterfalls.

After commando-rolling off a rock into the water, we initiated Nick, the groom-to-be, by making him roll in a reeking pool of mud.

Next was the rock climbing test. My fingers clung to the slippery rockface, struggling to hold my body weight as I pulled myself around the crag. One of our group, Judith, was not so lucky and only narrowly missed Evil as she crashed into the water below. Perhaps on purpose?

After we were pummelled while sitting under a waterfall, we climbed up through a tiny pitch-black tunnel, sliding on our bellies like worms. Then, leading us into an old dark mining cave, Evil showed us the igniting qualities of silica (once mined there) by lobbing it and waiting for the momentary spark as it hit the ground.

Back in the light, the final challenge had us crawling on a ledge behind a heavy curtain of water, and doing a Bond-style leap into the pool below.

But it was at the Gunpowder Works where we met the true Welsh dragon — Loonies’ Leap. The lesser-loonies could go for a 3m drop but it was the 5.5m plunge into a churning pool of water that was the real test.

By now nothing could faze me. Looking straight ahead, I crossed my arms, stepped out and joined the official wacky Welsh club.

Row your boat

Brave a torrent of rapids on the Wye River in a two-person canoe, dodging tree stumps, branches and river banks. Eventually the swirling eddies flatten out and you regain a sense of calm, gliding past willows and chirping birds.

Getting high

Make like Indiana Jones on a high-rope course, tackling a jungle gym of ropes, logs and swings. In a harness, the chances of plummeting to the ground are slim, but it does little to stop your knees shaking, especially at the last hurdle — climb a wobbly 12m wooden pole before taking a leap of faith to grab a swinging trapeze.

Black Mountain also offers white water rafting, hot dogging, rock climbing, archery, caving and more.
» Jo Cackett travelled with Visit Wales. For more info on places to see and stay, call 0800-915 6567 or see www.visitwales.co.uk.