Underwood Reservoir

The water sits perfectly still most mornings, reflecting the Welsh hills like a mirror someone forgot to tilt. Underwood Reservoir, just outside Chepstow, is the sort of place locals know about but visitors often miss - which is precisely why it's worth seeking out. You get a proper sense of the landscape here without the crowds that plague the honeypot spots.

It's a working water supply, so don't expect theme park facilities. What you do get is a decent walking circuit around the perimeter, with views across the water toward Monmouthshire's rolling countryside. The walk takes a solid hour at a steady pace, though you can dawdle longer if the light's good. Bring binoculars if you're into birds - herons and cormorants turn up regularly.

Families with older kids will find it straightforward enough. Younger ones might get bored after thirty minutes unless they're the type who enjoy a simple amble and spotting wildlife. The path's well-maintained but exposed in places, so wind can be a factor in winter.

There's no entrance fee as far as anyone can tell, though the reservoir's not really set up as a tourist attraction. Car parking is basic. It works well as a half-morning outing if you're staying at Penhein Glamping nearby - you can knock out a walk before breakfast, then head elsewhere for lunch. Not a day-long destination by itself, but a genuinely rewarding twenty minutes from Chepstow if you fancy some unvarnished Welsh water and air.