Steve48 posed the question and myWanderlust members responded with their most intrepid dips - from Afghanistan to Ecuador's Piranha Lake
As well as a number of Icelandic beaches – including a geothermal one with all the trappings of the seaside, one of Steve's most memorable swims was Lake Peipus on the border between Russia and Estonia. It's the largest transboundary lake in Europe. Hopefully Steve had a multiple entry visa.
Emma's dip in a tributary of the Amazon sounds idyllic - beautiful jungle surroundings and a small waterfall with a ledge behind it to duck on to. But it was the caiman-shaped rock protruding about an inch from the surface that made this a swim to remember.
Barrow is the northernmost point of the US. A dip in the Arctic Ocean here gains you membership of the Barrow Polar Bear Club. 'I had to go put my head in too, otherwise I wouldn't have got my badge,' says satkinson. 'It was jolly chilly, but fun!'
Plucky Sergeant Pluck took a dip in the only public pool in Kabul. The pool had been empty for ages and when he heard it had been filled he was at the front of the queue.
'They had indeed filled it...all the way up to about 18 inches deep,' he explains. 'Disturbingly, some of the locals started climbing up to the high board which is a proper 20m up. Fortunately, they realised that diving into 18 inches of water from 60ft wasn't really survivable.'
Pluck had time for a couple of lengths of breaststroke - trying not to swallow the water - before people started throwing masonry at him. A good day out, according to the Sergeant.
DrG just came back from the Top End and recommended a dip in Walker Creek in Litchfield National Park, near Darwin.
'If you reserve one of the walk-in camp sites you have exclusive use of your own plunge pool,' recommends the good doctor. 'I certainly did not feel the need for restrictions on clothing there.'
LS13 checked into a hotel in Burma at night during a power cut. Once settled into his room he opened the doors to the ground floor balcony and peered out.
'I couldn't make out anything in the gloom so stepped off to explore what I thought was the gardens,' he explains. 'Unfortunately it was a green slimy lily pond.'
LS13's partner dashed out on hearing the splash and saw him resurface from the stinking water like Martin Sheen in Apocalypse Now.
'Definitely one of my more unusual swimming locations!' he says.
David Ross took a dip in Piranha Lake in the Amazon rainforest in Ecuador three years ago and lived to tell the tale.
'They are apparently almost all harmless in almost all circumstances,' explains David 'Although I made sure the Ecuadorian tour guide went in first.'
David is quite the wild swimmer, it seems.
'I’ve also been swimming in Lake Titicaca (to the bewilderment of local women who were washing clothes in it), the Red Sea (with wild dolphins), the Dead Sea (where you can’t really swim, you just bob about), and Loch Ness (no hungry monster to be seen).'
Meet the Gringo went swimming with piranhas too, in the Bolivian pampas near Rurrenabaque.
'We had been fishing for piranha (and caught plenty) in the morning and then went swimming on the same stretch of river,' he says. To make things more interesting there were loads of big black caiman on the banks 20m away.
'The only reason it was safe to swim was because there were pink dolphins swimming around us,' he says.(Caiman don't go near them apparently). 'As soon as you lose sight of the dolphins it is time to get out of the water!'
'Me? I like my water warm like the sea at Anakena on Easter Island,' says salb. 'A touch of paradise!'
Birmingham Canal is not somewhere most people swim by choice. And neither did Roovilla.
'On a sunny summers day a very drunk then best friend of mine decided he was giving me a piggy back against my better judgement,' explains Roovilla. 'He got a little too close to the edge, and being a gentleman, as he lost his footing and started to lose his balance he decided to save himself and let go of me so I ended up in the canal! Definitely a [swim] I will always remember.'
A few years ago Steve trekked up to the base of Angel Falls in Venezuela.
'You can go swimming there in the pool formed at the bottom of the water fall,' he says. 'Great after sweating in the jungle... But the water was a lot colder than I expected!'
Have you got an unusual swimming experience you'd like to share? Add it by commenting below, or join in on the discussion over at Steve48's forum post here.