The Mayo Clinic attracts people from across the globe, which makes it one of the best places in the state to people-watch. Spend lunchtime in the main atrium of the clinic and you'll see people of all ages and cultures scooting about on their way to appointments. Former presidents, athletes, and the Dalai Lama all come to Mayo for checkups. Keep an eye out for the famous patients trying to go unseen, or eavesdrop on surgeons' conversations with co-workers. If you're really lucky, you might be there when a couple like Marlow and Frances Cowan, married 62 years, play one heck of a piano duet in the atrium. The charming Iowa pair struck up an impromptu concert in the building's atrium in 2008 and became YouTube superstars when a video of them went viral. They come through Mayo occasionally for medical checkups. They returned in February for another performance and packed the space with cheering fans.