Built for the 1962 World's Fair in a little over a year, and still the thing every establishing shot of Seattle uses. The observation deck sits at 520 feet with open-air glass benches that lean you out over the edge, and the floor below it rotates on glass — added in a 2018 renovation that stripped out the old revolving restaurant. On a clear day you get Rainier, the Olympics, the Cascades and the whole Sound at once. On the many days that are not clear you get cloud, which is worth knowing before you buy a timed ticket.