The John F. Kennedy Presidential Library & Museum is definitely worth a visit while in Boston. It's south of Boston's city center and away from all the crowds and sits right on the water so it's really calm and peaceful. The museum is full of memorabilia from JFK's life before and during his presidency and there is so much information that chronicles his life. There is also a patio in the back of the museum where John's boat is on display and where you can look out to the water. I would love to go back and browse through the library itself.