The biggest addiction in college: skipping class. Part of my job as an Admissions Advisor at Eastern Washington University is to give presentations to visiting middle and high school classes that come to see what a college campus is like.
The Athenian Agora. The Agora of Athens was the center of the ancient city: a large, open square where the citizens could assemble for a wide variety of purposes. On any given day the space might be used as a market, or for an election, a dramatic performance, a religious procession, military drill, or athletic competition.
Just be sure to wear comfortable walking shoes or allot extra time for moving around if you use a wheelchair, since Ancient Agora's pathways are covered in gravel. Ancient Agora costs 8 euros (about $9) per person to visit, or you can purchase a unified ticket for 30 euros ($32.50), which includes five consecutive days of access to Ancient Agora, the Acropolis and the Archaeological Museum of Kerameikos.