Did you know there are wonderful walking tours of Boston? They can take you down under the city or you can do an architecture tour. I have taken the architecture tour myself. It lasted about 1.5 hours and was very interesting. Not for small children (they get bored) but adults would love it. They explain the various types of buildings and what all the archways mean, when the buildings were built and what they were originally used for. The cost (at the time) was about 10.00 per person for a guided tour and it began and ended at Faneuil Hall so one could grab a few bowls of that wonderful chowder at the end!