Infinity London's 360-degree rooftop infinity pool will cost millions

Calling it a pool with a view would be a euphemism. London, England, will have the world's first 360-degree rooftop infinity pool, the highest in the world in 2020.

The pool will be built on the roof of a 55-story building, situating the 174-gallon pool at 200 meters (or about 656 feet) in the air, according to designer Compass Pools.

The pool will also have a transparent background.

The pool will be part of a new luxury hotel, Infinity London, which is also expected to open by 2020, said Alex Kemsley, technical director and pool designer, at CNBC Make It.

"We expect the fund itself to cost more than £ 10 million," he said, for $ 12.7 million.

The transparent floor of the pool, which will allow visitors to see people swimming and the sky above, will be cast acrylic (rather than glass) "so that the pool is perfectly clean", according to Compass Pools. The acrylic "transmits light at a wavelength similar to that of water," thus causing the effect, the company said.

The mechanism for entering the pool is based on the door of a submarine, and it features a "spiraling spiral staircase that rises from the bottom of the pool when someone wants to come in or out – the absolute tip of the design of the pool and building, so little James Bond to boot! "Kemsley said in a statement.

"Normally, a simple ladder would suffice, but we did not want stairs outside the building or in the pool, it would ruin the view," he said.

According to the website, an integrated "anemometer" that monitors the speed of the wind will prevent water from flowing into the street. The pool heating system will use lost energy from the building's air conditioning system.

If Infinity London is installed on the only 360-degree rooftop infinity pool, it will not be the only open-air pool you can access. The Marina Bay Sands hotel in Singapore features a rooftop infinity pool located on the 57th floor of the hotel (the views are not 360 degrees). It measures 492 feet long and stretches on three tower buildings. It is billed as "the world's largest rooftop infinity pool," according to the website. It opened in 2010.

Marina Bay Sands was one of the most Instagramed hotels of 2017, according to Travel + Leisure, which used the number of geographical tags for the ranking.

In Houston, the Market Square Tower Apartments, which opened in 2017, has a glass-bottomed pool 500 feet above the ground.

According to the website, the glass-bottomed "cantilevered on the roof edge" pool is located on the 40th floor overflow deck and is open to residents and guests of the luxury tower.