If you are looking to visit one of the tallest buildings in the world or, for that matter, experience one of the top ten observation decks in the world, you might want to start looking outside the USA. The Willis Tower in Chicago, IL currently ranks as the 9th tallest observation deck in the world and the only high rise in the United States in the top ten. However, it won't stay this way for very much longer. By 2020 the Willis Tower is expected to fall all the way to #17, and #18 by 2021.
The data below is according to The Council on Tall Buildings and Urban Habitat (converted from meters to feet):
The observation deck height is a far more meaningful number than the overall architectural height, as we know nearly all high rises add absurdly long antenna to the top of the towers for additional height "cred," which doesn't do us much good, besides making it harder to fit the full building in the frame of a picture.
Most of the new towers that are under development and are scheduled to be completed by 2020 are concentrated in to two regions: the Middle East and Asia. These markets have been booming recently and the competition for world records has been fierce in that part of the world.
But don't feel bad for our Willis Tower just yet. Barclays, one of the largest banks in the world, has released the SkyScraper Theory (ominous music). The Skyscraper Theory tries to draw a correlation between the completion of a tallest building in the world and an economic crisis. The theory goes one step further and alludes that the rate of the increase in height may also reflect just how big of a crisis there might be. So if your country is building a mega tall skyscraper...beware!
So if visiting the tallest observation deck in the world is on your bucket list you will need to start booking your tickets to Asia, but, hey, they could be really cheap after 2020 if that theory is correct.