A planned London skyscraper is being designed from the top down, and the entire roof will be a 360-degree infinity pool with unobstructed views on all four sides — as well as below. Compass Pools will craft the 158,503-gallon pool out of cast acrylic, and “a rotating spiral staircase, much like a submarine’s door, will arise from the floor of the pool” for entry and exit by guests of the hotel that will take up the top five floors of the 55-story structure. Read the Mashable story here