Willis Tower

 is a location in Watch Dogs. It is also a City Hotspot

History
The Willis Tower is the tallest building in the United States of America, standing at over 1,450 feet. One fun feature of the tower is the Skydeck, where you can feel the building sway in the wind and get a view of Michigan, Wisconsin, and Indiana. Or for you daredevils, the tower features glass balconies, so you can see why exactly you should be afraid of heights.

Summary
Willis Tower is a massive skyscraper featured prominently in Chicago, and was first seen during the E3 Gameplay Video. Its official address is 233 South Wacker Drive, Chicago, Illinois 60606. It is more commonly known by it's former name, the Sears Tower.