Isleham Nature Reserve

The Fen isn't everyone's idea of a day out, but if you're serious about birds and plants, Isleham Nature Reserve delivers in spades. It's a proper working wetland east of Ely, all reedy channels and open water where you can actually spot something worthwhile - marsh harriers, bitterns if you're lucky, and in summer the place erupts with dragonflies. The walking trails loop through the reserve, nothing strenuous, and there's decent viewing platforms so you're not wading through mud to see anything. Allow a couple of hours if you're doing the full circuit, less if you just want a quick poke about.

The thing about Fenland reserves is they're either magical or muddy depending on the season and your expectations. Spring and autumn bring the best birdwatching, winter's bleak, summer's sticky. There's no visitor centre to speak of, no gift shop, no cafe - you come here to be quiet and watch things, not to consume an experience. That's actually rather refreshing.

If you're parked at Trelander just down the road, this fits perfectly into a longer walking day around the local waterways. The landscape is flat and open in a way that grows on you. Not for restless kids, but ideal if you've got binoculars, a field guide, and the patience to sit still. Free access, naturally. Check conditions after rain - the paths can be sodden.