233 S. Wacker Dr.
Enter Skydeck on Jackson Blvd.
Chicago, IL 60606
The Sears Tower has officially been known as the Willis Tower since 2009, but 35 years of tradition is hard to break so the old name is still often used. Whatever you call it, the tower is the tallest in the Americas.
The Skydeck offers the best view in the city, and recently underwent a renovation. Part of the redesign added transparent balconies that extend four feet out from the building with a glass floor for views straight down to Wacker Drive. As if that wasn't scary enough, visitors can feel the entire building sway in the breeze on windy days.