Iron Trunk Aqueduct

You'll spot it long before you get there - a great metal trunk stretching across the Nene Valley like some Victorian engineering fantasy made real. The Iron Trunk Aqueduct is exactly what it says: a cast iron trough that carries water over the river, built in 1811 as part of the Grand Union Canal system. It's the sort of thing you drive past and think "what on earth is that?", then realise you've got to go back and have a proper look.

The structure itself is genuinely impressive if you're into industrial heritage. Walking underneath it, you can appreciate the sheer audacity of the thing - Victorian engineers basically decided water could flow through a metal pipe suspended above the river, and they just... did it. The engineering speaks for itself, but don't expect themed interpretation boards or cafes. This is raw infrastructure, full stop.

It won't take long. Twenty minutes of pottering around, maybe half an hour if you're photographing it from every angle. Best approach is from the towpath side, where you can walk right along the canal and see how the whole contraption works. It appeals mainly to canal enthusiasts and anyone with a soft spot for 19th-century industrial ingenuity - kids might find it interesting for five minutes before wanting to move on.

Milton Keynes is only a few miles away, so it slots nicely into a wider canal-walking trip. The Home Farm CL is reasonably close if you're basing yourself here for a few days. Free to visit, naturally. Go when the light's good for photographs.