Yes, you're at the right place. Willis Tower was the Sears Tower until mid-2009, when insurance broker Willis Group Holdings bought the naming rights. No matter what you call it, it's still the USA's tallest building, and its 103rd-floor Skydeck puts visitors 1454 feet up in the clouds. Glass-floored ledges jut out in mid-air and give a knee-buckling perspective straight down.
Enter via Jackson Blvd, then take the elevator down to the waiting area, where you go through security and pay admission. Queues can be up to an hour on busy days (peak times are in summer, between 11am to 4pm Friday through Sunday). There's a factoid-filled film to watch, and then the ear-popping, 70-second ride to the top. On clear days the view sweeps over four states.
For those who prefer a drink with their vista, the Gold Coast's John Hancock Center is a better choice.