Brocolitia Fort

The Romans chose this spot well. Perched on a ridge above the North Tyne Valley near Hexham, Brocolitia Fort sits where Hadrian's Wall cuts across the landscape - and what remains tells you exactly why they built it here. You're looking at the foundations of a cavalry fort from around 130 AD, complete with the outline of barracks, a commander's house, and what was once a proper military complex guarding this stretch of frontier.

Walking the site is free, and you'll need a good hour to actually take it in properly. The stone bases are weathered but clear enough if you know what you're looking at - bring a guidebook or use the interpretation boards scattered around. The views across the valley are genuinely outstanding, which obviously wasn't an accident when they sited it. Families with older kids who've got some patience for archaeology will find it absorbing; younger ones might run out of steam after thirty minutes of "looking at old stones."

Historically-minded walkers are the real winners here. It slots perfectly into a Hadrian's Wall walking holiday, especially if you're based at Stonehaugh Campsite or Sycamore Glamping Pods nearby. You can combine it with walking sections of the wall itself, visiting Chesters Fort just down the way, or exploring Hexham's abbey town proper. Go in spring or early autumn - you want decent light to actually see what's what, and you don't want to be scrambling about in mist.