Fourteen Swallets #13

The swallets near Ruthin are proper limestone sinkholes - the sort of thing that makes you realise the ground beneath North Wales isn't as solid as it looks. Fourteen of them cluster together in this particular stretch, each one a vertical drop where water vanishes underground, swallowed by the karst landscape. You can walk up close and peer down into the darkness, though most are just openings rather than accessible caves you can climb into.

This is walker territory, not a tourist attraction with a gift shop. The appeal lies in the geology and the slightly eerie feeling of standing above these sudden voids. Kids will find the holes interesting for about twenty minutes, then want to move on. Anyone with an interest in how water shapes limestone will get far more from it. The walk itself is pleasant enough, working through fields and farmland south of Ruthin, though there's nothing else to do once you've seen the swallets.

There's no entrance fee because there's no entrance - you're just walking on accessible land. Bring proper boots if it's been wet; the ground gets boggy. Allow an hour for the walk and looking about, maybe two if you're keen on the geology side and want to spend time at each one.

If you're camping at Clwydian Glamping Pods nearby, this makes a solid half-day outing to break up your stay. It's less showy than some North Wales attractions, but that's rather the point.