Compass Pools has unveiled a concept for a four-sided infinity pool atop a London skyscraper, accessed via a submarine-style door.
Called Infinity London, the project is described by the swimming pool manufacturer as "only building in the world to incorporate a 360-degree infinity pool".
The pool is imagined atop a 220-metre-high, 55-storey skyscraper. Containing 600,000 litres of water, it would be surrounded by clear walls made from acrylic.
The bottom of the pool would also be transparent, so it could act as a skylight. At night it would be lit up with colour-changing lights.
Swimmers would enter the pool via a submarine-style door
With no sides or deck, swimmers would have to enter the pool through a custom-designed hatch in the pool bottom. "We faced some quite major technical challenges to this building, the biggest one being how to actually get into the pool," said Alex Kemsley, founder and technical director of Compass Pools.

"Normally a simple ladder would suffice, but we didn't want stairs on the outside of the building or in the pool as it would spoil the view ? and obviously you don't want 600,000 litres of water draining through the building either," he added.
"The solution is based on the door of a submarine, coupled with a rotating spiral staircase which rises from the pool floor when someone wants to get in or out ? the absolute cutting edge of swimming pool and building design and a little bit James Bond to boot!"
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