Whitemoor Prison Nature Reserve

The reserve sits on the grounds of a working prison - yes, actually - which sounds dodgy until you realise the Cambridgeshire Wildlife Trust manages it properly and the whole setup works. You're walking through fenland habitat that's genuinely valuable, spotting lapwings and reed warblers without anyone asking what you're doing there. It's an unusual one, this.

March is the nearest town, unremarkable in itself but useful for supplies before heading out. The reserve itself is best visited in spring and early summer when breeding birds are active. You'll need wellies - it's fenland, so damp underfoot - and binoculars if you're serious about the birdwatching. Most people allow two to three hours, though you can do a quick circuit in an hour if time's tight.

This appeals most to keen birders and naturalists rather than casual family strollers. If the kids need proper paths and picnic tables, you'll find more comfort at the nearby caravan parks like Fenland Camping and Caravan Park or Knightsbridge Caravan and Marina Park, both within five miles. But if you're staying at any of them and want a proper nature fix - something genuine rather than managed prettiness - the reserve delivers. Access details aren't widely advertised, so contact the Wildlife Trust directly before visiting. It's the kind of place that rewards turning up properly prepared rather than assuming everything's signposted and sorted.