More than five decades after opening for the 1962 World’s Fair, Seattle’s iconic Space Needle needed a reboot. The revolving restaurant creaked in the flying saucer that architect John Graham conceived to top the slender tower. Guardrails, security cages, and other barriers added over the years blocked the view. Local firm Olson Kundig removed add-ons and in nearly every case replaced them with glass—10 different types of the material, weighing 176 tons in total, to be exact—all of it giving the 50,000-square-foot structure a brilliant new transparency. The firm wrapped the open-air upper deck in outward-tilting structural-glass panels—lean over the edge, if you dare—with integrated glass benches. A new spiral staircase winds down to a lower deck, which has what is being billed as the world’s first and only revolving glass floor. This dazzling feature provides never-before-seen views of the gears and motors powering the rotation, the elevators zipping up and down the column, and the landmark structure’s campus far, far below.