Chicago, located in the heart of the Midwest, features a thriving economy and world-class architecture. And Chicagoans think big. Three of the world's tallest buildings - the Willis Tower (1,450 ft), the Amoco Building (1,136 ft) and the John Hancock Building (1,127 ft) - are located here. And Chicago's O'Hare International Airport is one of the U.S.'s busiest airports. Whether attending to business or enjoying the sites, Signature-O'Hare has you covered.