Fourteen Swallets #14

The walk down to Fourteen Swallets starts innocent enough - a gentle descent through Welsh moorland just outside Ruthin. Then the ground simply opens up. These aren't grand caverns with tour guides and gift shops. They're a string of natural sinkholes where streams disappear underground into limestone crevices, each one marked by its own small entrance and the sound of running water echoing up from the dark.

What makes them worth the trip is the geology on display. The swallets themselves are frankly a bit underwhelming if you're after cathedral-sized caves - you're looking at holes in the ground, essentially. But stand at any of them and you're watching a working landscape, a river system doing what it's been doing for millennia. It's the kind of thing that clicks for keen walkers and anyone with even a passing interest in how water shapes rock.

This isn't a rainy-day activity. You'll want proper boots and dry conditions, as the paths can be slick and uneven. Allow a couple of hours for the full circuit if you're poking about at each entrance. It's free and unmanaged - no gates, no fees, no visitor centre. That's part of the appeal, though it also means going at your own risk.

If you're staying at Clwydian Glamping Pods nearby, this makes a solid half-day outing before heading back for a proper meal. It's not a standalone destination, but as part of a walking holiday in the Clwydian Range, it fills the gap between bigger attractions nicely.