Ogof Gwen Goch

The entrance to Ogof Gwen Goch is tucked into the hillside near Conwy, and you'll know you've found it when the air gets noticeably cooler and damper. This is a proper underground cave system - the kind where you actually need a torch and shouldn't wear your best trainers. It's not a tourist-polished show cave with handrails and electric lighting. What you get instead is raw geology and a genuine sense of exploration.

Inside, you're walking through passages carved by water over millennia, past formations that look like they've barely been touched since the last ice age. It's genuinely atmospheric, though the floor can be slippery and uneven, so this isn't the place for young kids or anyone with mobility issues. Serious cavers and geology enthusiasts will find it far more rewarding than casual visitors - expect to spend 45 minutes to an hour properly exploring.

Access details are tricky to pin down online, so ring ahead or check locally in Rhyl before you drive over. The cave is free to enter, but the real cost is the effort required to get there and navigate it safely.

If you're staying at Golden Sands or Parkdean Resorts Ty Mawr - both within easy driving distance - this makes a brilliant half-day adventure. It's the kind of thing that breaks up a standard holiday park week and appeals to kids who think they're proper explorers. Just bring a decent torch and sensible footwear.