Embassy Gardens is a housing development in progress in London. The design includes a pair of 10-storey apartment buildings. You will be able to walk between the two of them--or just swim!
The pool, which will rest 115 feet above the ground, is 90 feet long, 10 feet deep, and 19 feet wide. People will be able to see straight through the 8-inch thick glass walls. You can view more artist's conceptions at Contemporist.