Wigmore Castle

The ruins sit on a low mound overlooking the River Lugg, about four miles south-west of Hereford, and they're genuinely worth the short detour if you're camping in the area. What you get is a substantial Norman motte-and-bailey castle, though honestly the stonework is quite fragmentary - you're looking at bits of wall, some foundations, and the earthworks that give the whole thing shape rather than a dramatic keep looming over the landscape.

Wigmore has proper medieval credentials. It was built around 1070 and became the seat of the Mortimer family, who were serious players in English politics for centuries. Walk around the site and you can trace the defensive layout without too much imagination - the main mound where the castle stood, the bailey below it, the water defences from the river. It's the kind of place where history types will spend a good hour picking out architectural details, while kids might find it interesting for twenty minutes before wanting to move on.

The best part is the setting itself. The Herefordshire countryside rolls out around you, and on a clear day there are proper views. Admission appears to be free, and you can access it pretty much any time - there's no visitor centre or gates to manage. Allow an hour if you're serious, thirty minutes if you're just having a look.

It pairs well with a stay at Monstay Farm Campsite or Pearl Lake Country Holiday Park - both are close enough that you could visit as a morning walk before heading elsewhere. Combine it with the market town of Hereford itself, which has considerably more to keep a family occupied.