Bolingbroke Castle

The ruins of Bolingbroke Castle rise from the Lincolnshire flatlands like a stubborn reminder that something happened here - and it did, in 1399, when Henry Bolingbroke seized the English throne from Richard II. The castle itself is now little more than earthworks and fragments of stonework, honest enough in its decay, though it demands a bit of imagination to picture it as the powerhouse fortress it once was.

What you get is a walk around the moated site near Boston, poking at tumbled brick and masonry while the Fens stretch out around you. There's no visitor centre, no tea room, no queues - just you and some fairly substantial medieval engineering laid low by time and Cromwell's army. History types will find it worthwhile; the Henry Bolingbroke connection alone makes it worth the detour if you're interested in medieval politics and regicide. Families with restless children might find half an hour enough.

It's free to access, though there's limited parking and the site can be muddy after rain. Allow an hour if you want to walk the perimeter properly and read up on the plaques. Visit outside school holidays for peace and quiet.

Stay nearby at New Farm Holidays or Wood Farm Camping, both rated excellent, and you can combine this with other Lincolnshire attractions. It's the sort of place that rewards a morning visit before breakfast at your holiday park - quick, atmospheric, and free.