If you are scared of heights, this one is NOT for you. I had the pleasure of visiting Chicago in 2010 for the Taste of Chicago with my roommate from college, and could not leave without stepping on a glass balcony hanging 1,353 in the air. The famous Skydeck is 4 feet outside of the 103rd floor of the Willis Tower. With views that stretch for miles, somedays views extending up to four states, this is a must for all tourists!