Fourteen Swallets #6

A series of natural sinkholes and underground streams cuts through the hillside near Ruthin, creating what cavers and geology enthusiasts reckon is one of North Wales' most intriguing subsurface features. The fourteen separate swallets - that's the Welsh term for where surface water vanishes underground into cave systems - form a chain you can trace across the moorland, each one a dramatic funnel where the landscape simply drops away.

You won't find visitor facilities or marked paths here. This is proper adventuring territory, best tackled with an OS map, decent boots, and ideally someone who knows the area. Spring is ideal when water flow is highest and the sinkholes most dramatic - summer can see some nearly dry. Geology types and keen cavers absolutely love it; casual walkers might find a couple of the most accessible swallets enough before heading back to easier ground.

It's free to explore, though you'll need to navigate from the surrounding moorland yourself - there's no car park or entrance booth. Allow two to three hours to see several of the swallets properly. The landscape around here is wild and high, with views stretching toward the Clwydian Range.

If you're staying at Clwydian Glamping Pods and Campsite just down the road, this makes a solid half-day excursion for anyone interested in karst topography or simply wanting something different from the usual park-to-attraction routine. Not one for kids unless they're genuinely into caves and geology.