Rough Guides editor Rachel Mills goes deep underground in the heart of Snowdonia National Park to discover the latest, and craziest, adventure activity in North Wales.

A Victorian slate mine close to the town of Blaenau Ffestiniog was once where miners wielded hammers and chisels to eke out a hard living from the rock. Today, it's home to the world’s first subterranean trampoline. I went to investigate.

Yes, a trampoline in a cave

In fact, three giant trampolines in a cave twice the size of St Paul's Cathedral. Bounce Below came about after entrepreneur owner Sean Taylor saw a similar set up in the woods in France, but this is the first time it’s gone underground. Five hundred tonnes of rubble had to be removed from the cavern before the huge trampolines were strung up – the highest at 180ft – with chutes between each level and nets to stop the kids (and big kids) bouncing out.

Begin with trepidation...

This big kid is in her thirties and was feeling a fair amount of trepidation as our group crowded round to hear about the surreal activity we had signed up for. We grabbed helmets not dissimilar to those on a building site, except these were wet and smelled of cleaning chemicals. This was my first clue that things were going to get a bit sweaty.

We were then led through the damp and gloomy mines, ducking so not to hit our heads – the helmet wasn’t just a fashion accessory – and things got darker and colder the deeper we went.

Eventually we came into a huge cavern, which was ringing with noise like a crowded swimming pool on a weekend morning. I gazed up at the massive nets hanging suspended from the ceiling, illuminated with muted neon lights.

After another safety talk, which was mostly about not double bouncing the kids and taking the chutes (which I planned to avoid altogether) one person at a time, we were ushered across the walkway and into the initial practice zone, a quiet area where excited ten-year-olds bowled passed me to get to the good bit. As I wobbled from foot to foot, clinging to the netting at the side, I wondered if my day wouldn’t be better spent in a coffee shop somewhere warm. With a solid floor.

A drunk on a bouncy castle

Taking a deep breath, I launched myself through the gap and into the first zone.

It was almost impossible to stand and bounce in one spot as the trampoline heaved and pitched beneath my feet. As I bounced I was propelled from one side of the net to the other not unlike a drunk on a giant bouncy castle. It was very, very fun.

Trying to jump as high as possible, I went with it and tried, not very successfully, to stay on my feet. Before long I was exhausted and slightly hysterical, begging very small children to go and double bounce someone else.

Image courtesy of Visit Wales

Slides, walkways and shaky legs

There’s a narrow walkway (which thank goodness, isn’t bouncy), which takes you to the top trampoline 180ft off the ground. From here, it came as a bit of a shock to find out that the only way down was dropping feet first into a net chute sixty foot long and no wider than my shoulders. Luckily I heeded the warnings about covering your face with your hands as the netting whips against you as you plummet – another good reason for wearing something with long sleeves.

Slightly steadier on my feet by now, I happily bounced around the middle net before whizzing down to the lowest level where I had a well-earned lie down well away from the teenagers free running across the net.

The way up was a constricted walkway, likely made with very small cave trolls in mind, which I shuffled along, bent over double while it spiralled up for what seemed like forever. Emerging right back at the start, I was free to do it all over again. If only my legs would stop shaking.

Need to know

Restrictions

Weight: Max: 120kg Min: None

Age: Max: None Min: 7 (5 & 6 year olds by special arrangement)

Price for 1hr session

£20/person

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Header image courtesy of Visit Wales.