Motte & Bailey

A grass-covered mound rises abruptly from the Hertfordshire countryside east of Henlow, and that's essentially what you're looking at - a Motte and Bailey, the earthwork remains of a Norman fortification that's somewhere between 900 and 1000 years old. The mound itself is the motte, the bailey is the flat-bottomed enclosure beside it where soldiers and horses would have been stationed. It's free to visit and takes about twenty minutes to walk around properly, though you could spend longer if you're into medieval archaeology.

The appeal here is straightforward: it's a tangible link to Norman England without the crowds or entrance fees of a proper castle. History buffs will find it genuinely interesting - you can actually see how these quick-to-build fortifications gave the Normans military advantage across England. Kids will either think it's brilliant or boring depending on their age; under-eights will probably want to clamber on the mound for five minutes then leave.

There's no visitor centre, no café, no facilities. Go when it's not raining if you can, as the whole thing becomes rather muddy otherwise. It works well as part of a broader tour of Hertfordshire's Norman heritage rather than a destination in itself. If you're staying at Henlow Bridge Lakes or one of the other caravan parks in the area - Jacks Hill, Radwell Lake, or Almshoe Glamping - it's an easy local walk that breaks up a park holiday without demanding much effort. Bring decent footwear and manage expectations: this is archaeology, not entertainment.