Grim's Dyke

The earthwork runs for miles across Hertfordshire, a dark line through the landscape that tells a story nobody's quite certain about. Grim's Dyke is one of those archaeological features that makes you squint at the ground and wonder what Roman or Iron Age hands moved all this soil, centuries before anyone thought to name it after a grim old god.

It's not a polished visitor attraction with a car park and interpretive boards. You don't come here for a tidy morning out. Instead, you come to walk its length - and that's the whole point. The dyke runs as an embankment and ditch, often following field boundaries near Borehamwood, and the real pleasure is in spotting it, understanding how the landscape was once divided and defended. Serious walkers and archaeology enthusiasts will get the most from this. Kids might find a walk along ancient earthworks interesting for ten minutes, then get restless.

There's no entrance fee because there's no formal site to enter. You access it from public footpaths and nearby roads. Allow whatever time fits your walk - you could follow a section in an hour or plot a longer route if you're keen. Spring and early summer are best, when the grass isn't chest-high.

If you're staying at Home Farm Glamping or Aldenham Country Park nearby, Grim's Dyke makes a proper walk with actual historical substance, rather than just a circuit of a caravan park. It's the kind of thing that rewards curiosity more than casual strolling.