Most interesting • Skydeck Chicago debuted The Ledge in 2009, unveiling a breathtaking view of the city, 1,353 feet straight down to Wacker Drive and the Chicago River. Since then, it has become a “must-do” Chicago experience for locals and visitors alike. • The Ledge features glass panels that are 1 ½ inches thick and can hold 5 tons. • The Ledge’s glass boxes are designed to retract into the building, allowing easy access for cleaning and maintenance. • Approximately 1.4 million people visit Skydeck each year, a 30% increase in attendance since the debut of The Ledge. • On a clear day, you can see four states from Skydeck on the 103rd floor: Illinois, Indiana, Wisconsin and Michigan. Visibility from the Skydeck is approximately 40-50 miles (65 - 80 kilometers).