The Sears Tower is technically known as the Willis Tower now, after a London-based insurance group that obtained the naming rights in 2009. But no self-respecting Chicagoan is going to call this tallest building in the Americas, the Willis Tower. Financed entirely by the once-mighty Sears Roebuck & Co., the Sears Tower opened in 1973 and is still primarily an office building except for the popular observation deck - on one of Chicago's many windy days, you can actually feel the building swaying gently.
sa vaut le coup de payer 12$ pour apres avoir une vue panoramiqure sur chicago il y a meme des avancer en verre c'est super on a l'empression de floter a plusieur centaine de metre au dessus du sol a ne pas rater sous aucun pretex :)
I would skip on it, go have a cocktail on top of the John Hancock Building instead - will cost you around 12 $, get you an amazing view and drunk. If you don't want to spend any money at all - just take the lift up and check out the view from the bathroom window :-)