4. Notre Dame (1 hour) - A must see. Notre Dame is gorgeous and really does live up to it's reputation. It's free to go in, is open every day, and has a constant stream of visitors going in and out of it. To beat the crowds, visit as close to 8 am as possible. Also stop in at Shakespeare and Company across the street, an English bookstore that has been the home-away-from-home for dozens of famous writers and authors throughout the years. They also have a coffee shop, making this a great mid-morning stop.