Willis Tower, Chicago (must see)
Willis Tower, formerly named Sears Tower, is a 108-story 1,451 feet (442 m) skyscraper in Chicago, Illinois. At the time of its completion in 1973, it was the tallest building in the world, surpassing the World Trade Center towers in New York. Currently, Willis Tower is the tallest building in the United States and the fifth-tallest freestanding structure in the world as well as the fifth tallest building in the world to the roof. Skydeck Chicago at Willis Tower opened as The Sears Tower Skydeck observation deck on June 22, 1974. It is located on the 103rd floor of the tower. It is 1,353 feet (412 m) above ground and is one of the most famous tourist attractions in Chicago. Tourists can experience how the building sways on a windy day. They can see far over the plains of Illinois and across Lake Michigan to Indiana, Michigan and Wisconsin on a clear day. It takes about 60 seconds to soar to the top in either of two special, Schindler Group elevators.
Sight description based on wikipedia