At 110 stories and 1,454 feet tall (1,707 feet if you include the twin antennae), the Sears Tower is the tallest building in North America and arguably the world. Completed in 1973, it took three years and over $150 million to build. This was the second Chicago building designed by Bruce Graham and engineered by Dr. Fazlur Kahn of Skidmore, Owings & Merrill. They previously collaborated on the John Hancock Center which, at 100 stories tall, was no slouch in terms of height either. To brace against wind gusts that can cause the top of the building to sway by six inches, the Sears Tower is technically comprised of nine separate, interlocked buildings. Some of the world’s fastest elevators whisk passengers to their floors at speeds of 1,600 feet per minute nearly 20 miles per hour. On a clear day, the Sears Tower Skydeck (at a vertiginous 1,353 feet) provides 40 to 50 miles of visibility and views of Illinois, Indiana, Michigan and Wisconsin.