The Willis Tower (formerly the Sears Tower) in Chicago was once the tallest building in the world topping out at 108 stories and 1,451 feet in 1973. It has since been dwarfed by many structures. It is still an amazing building to appreciate when in downtown Chicago. It was especially thrilling to see it from several angles from the river. They recently build a new tourist attraction that would have been cool to experience, but not for the day after Thanksgiving – too many people. I caught these shots of the glass viewing rooms from the river.
Check out this video if you want to see how they made this.