Glass-walled swimming pools are all the rage on Instagram for one cheeky reason this summer
Women in bikinis are making full use of the glass walls, by pressing their bums up against the side for 'belfie' photo shoots
THESE days, selfies are almost as important as sun, sea and sand when taking a summer holiday.
The latest social media trend for vacation photos is cheekier than most though - and it's come about thanks to a rise in glass-walled swimming pools.
Hotels and beach clubs have started to build their pools with transparent sides - and Instagram users have inevitably turned them into a social media opportunity.
The glass-walled swimming pools allow people to see people swimming underwater from outside, which is perfect for people who like all eyes on them.
Women in bikinis are now making full use of the glass walls, by pressing their bums up against the side for photoshoots.
From Dubai and Mexico to Las Vegas, Instagrammers are leaving little to imagination as their share their new underwater "belfies".
If you're tempted to get on board with your own belfie photoshoot, here are some of the most popular see-through swimming pools around the globe...
Zero Gravity in Dubai
One of the most popular new belfie spots is Zero Gravity in Dubai, with its 39m glass-fronted infinity swimming pool.
On any given day, you're likely to spot party-goers pressing their bums up against the pool glass for a picture.
Mirage Hotel's Bar Pool Lounge in Las Vegas
Over in America, it's hardly surprising that Vegas is one of the trailblazers of the pool belfie trend.
The desert city is famous for its pool parties, with even the likes of Prince Harry attending a bash at the Encore Beach Club.
In the Mirage Hotel's Bar Pool Lounge in Las Vegas, swimmers can't take enough photos next to the pool's glass wall.
Carlota Hotel in Mexico City
The Carlota Hotel opened in Mexico City just last year, featuring contemporary art installations, impressive modern architecture and of course... a glass-walled swimming pool.
The pool's 30-metre glass walled pool is overlooked by a trendy bar and restaurant area, so swimmers can get maximum attention.
Laucala Island Resort, Fiji
Probably the photo that started it all - this picture was taken at an exclusive hotel in Fiji and has been shared thousands of times in various forms online.
The privately owned Laucala Island is one of a triplet of small islands that lie to the east of Thurston Point on the island of Taveuni in Fiji.
Set over 1,400 hectares, this is one of the most exclusive resorts in the South Pacific and the ultimate location for an underwater "belfie".
Mercu Summer Suites, Malaysia
And here's one for the ladies.
This joker got in on the act in the glass pool at the Mercu Summer Suits in Kuala Lumpur, Malaysia.
The real estate in Kuala Lumpur's exclusive business district has a floor with pod capsules on it, which you can rent for around £10 a night.