A giant underground trampoline has opened in a cave in Wales

Rough Guides editor Rachel Mills goes deep underground in the heart of Snowdonia National Park to discover the latest adventure activity in North Wales — an area that's known for delivering some of the best adventure holidays in Wales.

A Victorian slate mine close to the town of Blaenau Ffestiniog in Wales 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 giant undergound trampoline in a cave in Wales

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. 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. With the highest at 180ft, there are 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. 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.

From here we entered the 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.

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. Here 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

• Under 13-year-olds need to be accompanied by a participating adult
• 13-17-year-olds require a spectating adult
• Long sleeved trousers and tops are advised
• Prices per 1hr session start from £20/person
• Charge for spectators is £5/person

What else can I see and do in Blaenau Ffestiniog?

Sitting at the head of the green and pleasant Vale of Ffestiniog, Blaenau Ffestiniog (or “Stiniog” as it’s often called locally) grew from the its nineteenth-century slate quarry slate industry. 

Today the legacy of this industry lives on the re-purposing of slate caves into the trampoline experience, and other slate-themed tours and activities. These include zooming down Europe's first four-person zip-line, and touring a deep mine.

Beyond this, visitors can enjoy the fun thrills of the narrow-gauge Ffestiniog Railway, which winds up from Porthmadog. 

Meanwhile, if you’re into biking, Antur Stiniog is home to no fewer than 14 mountain bike trails. Offering routes for all abilities, the speedy uplift shuttle makes it possible to cover 10-15 descents in a day.

All that considered, it’s clear to see why this region — and Wales more widely — is a top place to travel more responsibly. For example, the repurposing and regeneration of the likes of slate quarries improve the environment and local economy in one fell swoop.

With that in mind, read up on practical ways to travel better in Wales. From foodies and families, to wildlife-watchers and adventurers, sustainable Wales has plenty to offer every type of traveller.

And, if you fancy getting off the beaten track, there are plenty of places to go green in Wales while doing exactly that. 

Where to stay in Blaenau Ffestiniog

• Best for mountain views: Isallt Guest House. A well-priced B&B in a Victorian house by the station.
• Best for families: Bryn Tirion. A charming three-bedroom holiday cottage with garden.
• Best for foodies Plas Weunydd. Run by Llechwedd Slate Mine, this super hotel offers top-draw breakfasts and electric car-charging. The same management also offer superb safari tents on the hills overlooking the quarry. 

Explore more places to stay in Blaenau Ffestiniog.

Where to stay in Snowdonia

Given that there are so many unforgettable things to see and do in Snowdonia National Park, who wouldn’t want to spend more time exploring this awe-inspiring area?

If that’s what you’re thinking of doing, get yourself a copy of Rough Guide Staycations Snowdonia. In the meantime, here are our recommendations for top places to stay in Snowdonia.

• Best for Italianate elegance: Hotel Portmeirion Village. Equal parts grand and eccentric. Former guests include H.G. Wells, George Bernard Shaw and Noël Coward.  
• Best for romantics: Mary's Court Guest House, Betws-y-Coed. Cosy, quaint comfort in the heart of Snowdonia National Park.
• Best for history buffs: Plas Dinas Country House, near Caernarfon. The ancestral home of Lord Snowdon offers personal service at a very personable price.

Browse more places to stay in Snowdonia, and read up on places to stay in Wales for a sustainable trip.

If you fancy bouncing underground, or zipping, hiking and biking overground in this area, get yourself a copy of The Rough Guide to Wales, and read our run-down of five eco-friendly holiday ideas in Wales. 

Not sure when to travel? Discover rewarding, sustainable trips for every season, and download a free copy of The Rough Guides to Responsible Wales. Yep, you read that right — totally FREE, this ebook will help you plan your trip with peace of mind.

Not a fan of planning? Browse our suggested Wales itineraries. As with all Rough Guides' tailor-made trips, they're 100% customisable. This means they can be adapted to cover everything from visiting the best castles in Wales, to hiking Pembrokeshire's epic coastal path and discovering Wales' best beaches.

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Header image courtesy of Visit Wales.