Milecastle 37

Milecastle 37 sits on Hadrian's Wall near Hexham, and it's one of those Roman remains that genuinely stops you in your tracks. You're standing at a proper garrison - small fort, really - where soldiers would have lived and controlled movement along this 2,000-year-old frontier. The stone walls are still there, built by hands that have been dust for nearly two millennia. It's free to visit, which is brilliant, and you can wander the site at your own pace without any faffing about with tickets.

What you see is fairly bare - don't expect reconstructed buildings or visitor facilities. It's archaeology in its purest form: foundations, walls, the landscape itself telling the story. That's exactly why it works so well. Historians and anyone seriously interested in Roman Britain will be absorbed for a good hour or more. Families with young kids might manage thirty minutes before asking to leave, unless they're really into forts and ancient walls. The walk itself is lovely, along the wall's ridge with proper Northumberland views stretching out.

Stay at Stonehaugh Campsite or Langley Dam Glamping nearby, both highly rated, and you're positioned perfectly for exploring this stretch of the wall properly. Visit off-season if you can - fewer people, better light for photographs, and the Roman stones seem somehow more real when you're not jostling crowds. Allow at least two hours if you're doing this properly, including the walk to get there.