Paddle between black lava rocks on the northwestern tip of Madeira. These crystal-clear paddling spots were formed when volcanic lava bubbled furiously into the sea and settled to form a natural rock pool. Despite being tamed for swimming purposes (with added steps, and a few perky parasols), the natural waters are strikingly superior to any hotel pool we've encountered. Head out in the morning, pay the £1.25 entrance fee and flop on a sun-drenched sun lounger for a few sizzling hours by the pool. It's the perfect place to perfect your crawl (read: cool off between tanning sessions).

A curved slice of Riviera life awaits at this Cote d'Azur stalwart. Perched above the ochre-red rocks that lend the hotel its name, the 50-key stay's pièce de résistance is its ocean-dipping pool carved into the rocky coastline of France's southern shore. Hotel residents can wind their way through fragrant gardens planted with tamarisk, thyme and mimosa to spend the early afternoon flat-out on crisp-white sun loungers under a periwinkle sky, a rosé spritz in hand. When the Gallic sun gets too much, cool off with a slow lap (or self-brine) in the 30m pool. Fed by the lapping waves of the Med, this is the real deal as far as Cote d'Azur living goes. Dinner at the hotel's Michelin-starred restaurant Récif is similarly ocean-focused, with fresh-off-the-fishing-boat seafood taking centre stage.

The subtropical Canary Island climate and a refreshing ocean pool make good bedfellows. Take a dip at this secluded swimming spot at sunset for primordial views across the spectacular Los Gigantes cliffs on Santiago del Teide's coast. Charco de Isla Cangrejo is our sea pool of choice when avoiding the towel-swamped beaches of the island's high season. Few dare edge down the set of spine-tingling cliffside steps to access the semi-circular pool, but join the intrepid handful and you'll be rewarded with a cooling soak in the natural swimming pool, and rocky patches perfect for a tapas-packed picnic. Just be aware that high tides and strong waves can combine dangerously: don't swim if the waves are breaking over the wall.

Built in the Sixties between the custard-yellow rocks of one of Northern Portugal's longest beaches, the sparkling pools of Piscina das Marés give us serious long, hot summer vibes. Linked by sand-brushed concrete walkways, the two pools disappear into Leça da Palmeira beach, a seamless soldering of public space and natural beauty dreamt up by Portuguese architect Álvaro Siza Vierira. Submerge your toes in the Slush Puppie-hued salty waters, crack open an ice-cold Sagres from the beach bar and toast Siza Vierira's vision from your poolside perch. For dinner, pootle down the coast to Boa Nova Tea House - an intimate seafood restaurant housed in a singularly striking property, also designed by Siza Vierira.

Tiptoe along hand-hewn tunnels, through the layers of caramel-coloured rocks that make up Devon's northern coastal cliffs, to find this hidden swimming stretch beneath the seaside town of Ilfracombe. Created by Welsh miners in the 1820s, the burrows lead to the pitmen's legacy: between two sheltered, silver-pebbled beaches sits an ocean-fed sea pool. You'll need to time your visit right; the pool appears above the tumbling waves for just three hours each side of low tide, and is only open in the warmer months. Practise your stroke, then scooch along the coast for further rock-pool explorations at Combe Martin.

Sea-gazing Croatia lacks the white-sand excesses of some of its Mediterranean neighbours, but it more than makes up for its beach deficit with great swathes of rugged, rock-strewn shoreline lapped by the jewel-like Adriatic. Who needs beaches anyway? Upon arrival at the white-stone Hotel Excelsior, just outside of Dubrovnik, guests should head straight for the diminutive measure of marine-blue seawater held tight by honey-coloured stone on its sea-facing side. Though small, the sea pool offers a brisk, post-flight refresh, plus an introduction to the hotel's jaw-dropping view of Dubrovnik's red-roofed old town. The historic 20th-century villa-turned-hotel has long been a nucleus of glamorous living: past guests include two rather regal Elizabeths: make like Hollywood royalty Taylor, or the UK's monarch, and sink into the salt-washed depths.

Fierce and furious Atlantic currents keep all but the most intrepid surfers out of the water on the salt-sprayed beaches of Bundoran's Tullan Strand in Donegal, but gamble a little way down the coastline and you'll find Nun's Pool (or, officially, West End Pool). Separated from the grumbling seawater by a barnacle-studded breakwall, the tidal pool was given its nickname thanks to its proximity to a former convent. This being Ireland, we'd err towards sisterly dress for a dip (no word on whether the nuns ever actually ventured in) - a wetsuit wouldn't go amiss.

Take the plunge on balmy Devon mornings at this au naturel saltwater swim spot. Hidden away on a private tidal island retreat, the rock-ringed pool offers early-morning invigoration for residents of the art deco Burgh Island hotel. Head down for a dip at noon, followed by an hour under the sun on the pool's raised central platform. Some might find the Jazz Age-esque hotel experience a little overwhelming - if this sounds like you, opt, instead, for the charming Artist's Studio, above the island's only pub.