The Scarlet sells itself as "an eco-hotel for grown-ups". That means relaxation rooms slung with hovering, adult-sized nap cocoons, an Ayurvedic spa and a seriously special restaurant which serves the sort of seasonal curiosities that would be lost on younger palates (sorry kids). Nowhere is its do-good, feel-good ethos better demonstrated than in the pool - a cradle of fresh saltwater, naturally filtered by reeds, which looks out over the regular swill of surfers cutting shapes on Mawgan Porth's Enid Blyton-perfect beach.

Lodore Falls, so-called for its location right next to its namesake higgledy-piggledy waterfall, is a must-visit for those who appreciate hiking, wild swimming and luxurious, man-made pools in equal measure. It looks out over Derwentwater, a serene spot to make a splash and not to chilly either if you visit in late summer. The hotel's heated hydrotherapy pool is as magical on a blue-skies day as it is a rainy one, when puffs of steam float on the water's surface, adding to the craggy scenery's palpable melodrama.

City-centre hotels with open-air pools get gold stars in our books. What could be better after a long day in town than a refreshing dip before heading back out for dinner? The King Street Townhouse's pool is a slate-grey cave, carved into the hotel's seventh floor and looking out over the pointy spires and iconic clock tower of Manchester Town Hall. The pool forms part of the hotel's spa offering, along with a glowy steam room and an ambient "relaxation area", so leave your racing-stripes at home and order a ginger tea (or a spritz) instead.

The Curtain is a members' club that doesn't shout for attention. Unassumingly tucked away from Shoreditch's main drag, The Curtain is known by a select few Londoners for its effervescent timetable of alternative workshops and events, as well as its really quite gorgeous rooftop bar and pool which are scattered with fairy lights and the whispering fronds of tropical pot plants. While the Curtain is taking room bookings, the pool isn't open for use just yet, so book ahead if you fancy taking a dip. Here's to an Indian summer.

The pool at this 18th-century farm turned millennial summer hideout is quite something. It's an exercise in bucolic perfection which spills out of a rickety-looking (though unmistakably zhuzhed-up) old boathouse and into the rolling, grassy surrounds of rural Oxfordshire. As any Soho House group veterans know, the emphasis here is on having a good time. Clad in timber, scored by golf buggy taxis and with more sporting activities than you can shake a racket at, it's about as close you can get to an American country club without leaving home turf.

Newquay isn't quite the hotspot it once was, but stylish hotels such as Watergate Bay, which is just a short scooch along the coast, offer exciting glimpses of what it could become. Self-styled epicureans should hunker down for this hotel's food offering alone; it has five restaurants (yes, five) but only 71 rooms, meaning you have your pick of local Cornish fare and ocean-view tables whatever the weather. As for the pool, this is the real deal - a long one for both lapping and lounging - cornered by a floor-to-ceiling glass partition which collapses onto the cliffside.

Not overcooked or underbaked, and dusted with the perfect balance of modern flourishes and old-school touches, Cowley Manor is a country house hotel done just right. You'll find its pool nestled among the mansion's 55 acres in a sandy-hued, walled garden. Fringed with jumbo-sized outdoor beanbags and lean, almost Bauhaus-esque sun loungers, the pool is very much a destination in its own right. When you aren't lolling about by the pool ladder, you'll be fighting the urge to Insta-spam your friends. It really is that pretty.

If Hambleton Hall was a person it'd likely be a glamorous grandma, the type to clutch her pearls and heat-brush curl her hair. It's a charming and eminently well-to-do hotel, albeit a little old-fashioned for our liking. Regardless, its pool is like a precious relic from the past. Cosseted away from the Victorian house by a red-brick rood screen interwoven with trailing flora, it's a timeless English beauty simply begging to be painted in loose puddles of watercolour.

A 20m-long garden swimming pool inlaid with chequerboard tiles. Would you expect anything less refined from Beaverbrook, Surrey's foremost country house hotel? This pool is like a Slim Aarons photo come to life, set among meticulously clipped lawns and lined by two faultless rows of snow-white loungers, punctuated by taut canvas parasols. Though the outdoor pool is a relatively recent addition to the 150-year-old mansion, it's just the sort of place you can imagine Beaverbrook's legendary former guests (Liz Taylor and Jean Cocteau, being two) flopping out on a balmy summer's day.