The Chicago marathon was by far the most incredible running event I have ever experienced. Running with 45,000 other marathoners through streets lined with 1.2 million spectators is something that every marathon runner should experience. Seriously, run the Chicago marathon! The race is well organized and the city is beautiful, especially when the weather cooperates: can't beat 55 and sunny. My mom and cousin joined me for 4 days of marathon-centric Chicago site-seeing. It was an experience of a life time.