Walking On Air

The platforms are made op water-white glass, with no visible frame, and will stick out 1,353 feet above the street.

"In addition to delivering a gut-wrenching experience while ensuring no one actually plummets to the ground, the designers had to contend with one other factor: the window washing system. The glass boxes promised to be a real impediment to the facade-access baskets, which drop straight down the building’s face.

In answer, SOM designed The Ledge’s modules to retract into the building."