Wilstone Reservoir

Water, sky, and the occasional heron - that's the draw at Wilstone Reservoir, just outside Tring in Buckinghamshire. It's a proper working reservoir, so don't expect manicured banks or visitor centres. What you get instead is a 125-acre expanse of open water where locals come to walk, birdwatch, and occasionally fish. The perimeter path is well-trodden and takes a good hour to complete at a leisurely pace, with decent viewing points dotted around. Birdwatchers rate it highly - great crested grebes, coots, and if you're lucky, something rarer will turn up. The landscape is flat Hertfordshire farmland, which means proper big skies and nowhere to hide from the wind.

Families with young walkers will manage it fine, though there's not much in the way of playgrounds or facilities - bring a packed lunch. It's genuinely free and open access, which is refreshing. Winter and early spring are prime birdwatching months when migrating species pause here. Summer gets busier with dog walkers. If you're staying at Chiltern Yurts just 1.3 miles away, or any of the other camping spots scattered around the area, this is an easy morning or afternoon out. It won't blow your mind - it's functional rather than dramatic - but it's a solid, uncluttered break from car parks and admission fees. Go for the walk, the air, and the genuine chance of spotting something interesting through binoculars.