Kielder Castle

The castle sits right at the edge of Kielder Water, a sprawling reservoir that dominates this corner of Northumberland. What you're actually looking at is a pele tower - a fortified stronghold built in the 1400s - though the Victorians gave it a proper romantic makeover that's a bit at odds with its brutal origins. Inside, the visitor centre covers the area's border history and the reservoir itself, which took over the valley in the 1980s and drowned several villages in the process. It's sobering stuff, frankly.

Walkers will find this useful as a waypoint rather than a destination in itself. The views across the water are decent, and you're well-positioned for trails heading into the forest that swallows most of this landscape. History buffs should allow an hour to look round properly - the pele tower tells a gritty story of Tudor-era raiding and survival. Families with younger kids might find it a bit thin on entertainment beyond the gift shop, but the location itself is dramatic enough to hold attention for a bit.

If you're camping at Kielder Campsite just half a mile away, it's an obvious half-hour call on a drizzly afternoon. The nearby Landal and Waterside lodges give you more comfort - and better access to the water itself - but the castle works as a morning stop for any of them. Hexham is the nearest proper town if you need supplies, though it's a fair drive away. The castle's free to wander the grounds, though admission to the centre itself requires checking ahead.