The tallest building in the world is the Burj Khalifa in Dubai, but the United States boasts plenty of vertical treasures worth marveling at -- especially on Skyscraper Day, Sept. 3, the birthday of architect Louis Sullivan, whose work in the 1890s helped make today's structures possible. Here are the 20 tallest buildings in America, according to the nonprofit Council on Tall Buildings and Urban Habitat, based on height from the "lowest, significant, open-air, pedestrian entrance to the architectural top of the building, including spires." Some of these buildings share their views with the public, and there are deals and budget-friendly tips to alleviate occasionally pricey admission fees. But skyscrapers can inspire just as much awe when seen from street level.
Related:25 Places to Enjoy Rooftop Views Without High Prices