Instead of staying in air-conditioned spaces, Londoners would choose to cool off at a midair see-through swimming pool this summer. /CFP

The world's first 'sky pool' is 25 meters long and suspended 115 feet in the air between two 10-story residential buildings in Nine Elms, south London. The location gives swimmers a unique view of the London Eye and Westminster. /CFP

The swimming pool is three meters deep with a bottom 300 millimeters thick and completely made of acrylic. Architects Arup Associates, engineers Eckersley O'Callaghan and aquarium designers Reynolds joined hands to design the structure and finish its construction. /CFP

"Once you swim off, you can look right down. It will be like flying," said Brian Eckersley, director of Eckersley O'Callaghan. /CFP