Monmouth Castle

The castle sits right in the middle of Monmouth, on a grassy mound that rises above the town centre - you can't miss it, really. What remains is mostly the Norman keep, a solid stone drum that's genuinely impressive when you walk round it, especially if you catch the light on those weathered walls. Inside, the spaces are fairly open - there's a small museum that covers the castle's role in the Civil War and its earlier medieval importance, but I'll be honest, you're not spending hours in here. The real draw is scrambling up the mound itself and getting views across the town and the Wye Valley beyond. On a clear day, it's properly worth the short climb.

Families with older kids will enjoy it more than toddlers - there are steps and narrow passages that need a bit of agility. History buffs should definitely call in, particularly if you're interested in the English Civil War. The locals have done a decent job maintaining it without turning it into some over-restored theme park attraction.

It's free to wander the grounds, which is a bonus. Allow an hour if you're thorough, 20 minutes if you just want the quick look and the views. The town itself - Monmouth - is worth poking around after, with decent pubs and a proper high street. If you're based at Trippenkennett Farm near Coleford, this makes for an easy afternoon trip, breaking up a forest holiday nicely. Six miles or so from the campsite, so no distance at all.