Lincoln Castle

Standing on the hill above Lincoln, the castle's Norman walls are impossible to miss - they've dominated this skyline for nearly a thousand years. What you're looking at is one of only two castles in England with a double motte, which basically means two massive earthen mounds. The keep itself is genuinely impressive, and walking the walls gives you proper views across the city and surrounding countryside. Inside, there's the chance to see the Magna Carta - one of only four surviving copies - which does make the whole thing feel a bit weightier than your average castle visit.

History buffs will spend a good two hours properly exploring. Families with younger kids might find the walls a bit much, though if yours are keen climbers and keen on medieval warfare, they'll eat it up. The ramparts are steep in places, so factor that in. Allow at least an hour even if you're just doing the essentials.

It's free to wander the grounds and walls, though there's usually a charge if you want access to the keep and the Magna Carta exhibition - check ahead as opening hours can be patchy. The castle sits right in Lincoln itself, making it an easy add-on to a broader East Midlands trip. Several decent caravan sites sit within a few miles - Hartsholme Country Park is barely two miles away and well-rated, or South Cliff if you fancy something equally good. Either base would let you tackle the castle in a morning, then explore the cathedral or the Roman Newport Arch without faffing about.