The 5th highest building in the United States and the 28th highest building in the world as of now, has been the world’s tallest for almost 40 years. Now this Art Deco iconic skyscraper can be climbed by two separate stairways. You can walk the 1576 steps to the observatory on the 86th floor and then another 284 to the mooring on the 102nd floor. Altogether it’s a whooping 1,860 steps and that’s quite a workout. Bring a lot of water.