6. Coryvreckan Whirlpool, Scotland
Swimming the Coryvreckan is not a challenge to be taken lightly or without local advice – in fact George Orwell nearly died here crossing from Scarba to Jura in a boat. Created by a rocky pinnacle below the surface of the sea, the whirlpool varies in strength depending on the tide and winds, and it’s possible to swim right across when it’s at its weakest.
7. Badeschiff, Berlin
A semi-wild outdoor swimming spot, Berlin’s Badeschiff is a stylish urban pool made from an old river barge, which floats in the slightly less appealing waters of the River Spree. On summer days music blares and Berlin’s hipsters fill the sandy beach, and in winter they take refuge from the harsh weather under a cosy polytunnel-like roof.
8. Fraser Island, Australia
A UNESCO World Heritage Site and the world’s largest sand island, Fraser Island is undeniably idyllic. The surrounding sea is home to some dangerous currents, as well as plenty of sharks, so your best bets for swimming are inland spots such as Lake Wabby and Eli Creek. Be sure to get local advice about the whereabouts of the island’s crocodile residents before you dive in.
9. Crystal River, Florida
Crystal River’s eponymous waterway is blessed with supremely clean water and fed by around forty freshwater springs. This serene spot is a magnet for manatees, gentle giants more closely related to elephants and aardvarks than to other sea life. Crystal River is the only place in Florida where you are permitted to swim with these curious creatures – an encounter not to be missed.
10. Bimmah Sinkhole, Oman
The perfect spot to escape the searing Omani heat, the Bimmah Sinkhole is a tranquil spot along the coast southeast of Muscat. Part of the Hawiyat Najm Park, the exterior has been rather sanitized with handrails and steps, but the pool itself has lost none of its magic; myriad shoals of tiny fish are testament to the purity of the vodka-clear water.
11. Pelican Bar, Jamaica
We don’t condone swimming on a full stomach (or with a belly full of rum), but Jamaica's Pelican Bar is truly irresistible. Accessed by boat, the sand bar around this spindly structure is the perfect place to spend a lazy day snorkelling in the turquoise waters, drinking coconut punch and snacking on fresh fried fish. Make sure you keep your eyes peeled for dolphins.
12. Seljavallalaug, Iceland
Forget the rampant commercialism of the Blue Lagoon, Seljavallalaug is our top pick for a raw and rugged outdoor swimming experience in Iceland. The perfect spot to dive in and drop off the radar, the squat, rectangular pool is fed by a natural hot spring.
13. Havasu Falls, USA
You probably wouldn’t normally associate Arizona and the region around the Grand Canyon with lush waterfalls and wild swimming, but the nearby Havasupai Reservation is home to several such cataracts. Most impressive are the 45-metre-high Havasu Falls – gorgeous turquoise cascades that burrow deep into the Havasu Canyon as they flow over a series of curious travertine rock formations.
14. Donsol, the Philippines
Home to one of the world’s largest populations of whale sharks, Donsol is the perfect spot to “go large” on your wild swim. You might want to watch out for the odd careless flick of a gargantuan tail, but the whale sharks are filter feeders, so swimmers have little to fear from these leviathans.
15. Cwm Cau, Wales
Legend has it that if you spend a night at the top of Cadair Idris in Wales you will die, become a poet or go mad, but the views are worth the risk. Crater-like Cwm Cau, nestled on the top of the mountain, is the perfect spot to cool off after the hike up.
16. The Devil’s Pool, border of Zambia & Zimbabwe
Next time you’re wallowing comfortably in the bath, spare a thought for the souls brave enough to swim in the pool of the Devil himself. Perched a stomach-lurching 360ft above Victoria Falls, this swim is only possible when water levels are low or else you’ll bob straight over the cascade below.
17. Crater Lake, USA
A dramatic vertebra on the spine of the Cascades Range, Crater Lake is an extinct flooded caldera containing the deepest lake in the USA at almost 2000ft. Visitors can swim safely at the end of the Cleetwood Cove Trail; the still water reflects the sky above like a huge convex mirror while sheer cliffs loom dramatically on all sides.
18. Kouang Si Falls, Laos
Whether you approach by boat down the Mekong River or in a tuk-tuk from Luang Prabang, the Kouang Si falls will still take your breath away. A multi-tiered cascade some 60m tall, there are multiple, heavenly-looking pools here. Swimmers should head for the lower pool, not far from which is a small meadow that is a haven for butterflies.
19. Gunlom Falls, Australia
Gunlom is a stunning series of falls and pools – including one with a natural infinity edge – boasting great views and a shady campsite. Accessed via an unsealed road and immortalized in the film Crocodile Dundee, make sure that you take local advice before diving in – there are thousands of salties in Kakadu National Park, although few make it up to this altitude.