Pant Mawr

The entrance to Pant Mawr sits tucked into the limestone hills near Swansea, and the moment you duck through it, you're in another world entirely. This is a proper cave system - the kind that rewards a bit of scrambling and doesn't mollycoddle you with handrails or electric lighting. You'll need a torch, sturdy boots, and a willingness to get muddy. The passages open up into chambers with decent headroom, and there's something genuinely thrilling about moving through rock that's been carved out over millennia, especially with nothing but your own light to guide you.

It's brilliant for anyone with a taste for adventure caving without the serious technical challenges. Kids old enough to handle confined spaces and uneven ground will find it genuinely exciting - proper exploring rather than a guided walk. Adult cavers and geology enthusiasts will appreciate the formations and the sheer fact of being underground. You're probably looking at a couple of hours if you take it slowly and enjoy the spaces, though you could move through faster if you wanted.

The nearest town is Swansea, though the cave itself sits in the wilder heart of Powys. If you're based at one of the nearby parks - Brecon Beacons Camping & Caravan Park or any of the glamping options dotted around - Pant Mawr makes an excellent half-day expedition. It's the kind of place that makes you feel like you've actually discovered something, rather than simply ticked a box.