Green Lagoon

The water here is an unsettling shade of turquoise - not the kind you'd expect in rural Hertfordshire, but that's exactly what makes Green Lagoon worth a stop if you're staying at Ashridge Farm Caravan and Motorhome Club Campsite nearby. It's a flooded chalk pit, basically, which explains the colour and the slightly eerie quality of the place. The lagoon sits east of Henlow and has become something of a curiosity for locals and visitors alike.

There's not a huge amount to do here in terms of structured activity - this isn't a visitor centre with cafes and gift shops. What you get instead is a short walk around the water's edge, decent photo opportunities if you're into that sort of thing, and the oddly compelling sight of the brilliant blue expanse surrounded by chalk-white banks. On a clear day it's genuinely striking. The walk takes maybe thirty to forty minutes at a leisurely pace.

Families with younger kids might find it interesting for half an hour or so, though there's not much to keep them engaged beyond looking at the water. Photographers and anyone with a thing for industrial heritage will appreciate it more - there's something intriguing about how nature's reclaimed this old extraction site. Walkers passing through the area should definitely factor it in.

It's free to visit and accessible year-round, though obviously it's more pleasant in decent weather. If you're based at Ashridge Farm for a week, slot it in as a half-hour diversion rather than a main event. It's quirky enough to be memorable, but don't make a special journey.