There are two major destinations in Mystic, CT, the Mystic Seaport and the Mystic Marine Life Aquarium. The seaport boasts a number of “tall” ships dating back to the whaling era, if you've ever read Moby Dick, you are familiar with the Pequod and you will feel right at home.
The aquarium is just as much fun with the new penguin exhibit and the always awesome jellyfish. Try to go on a week day and hopefully you will catch a second grade class trip. Grab a great dinner at the the Daniel Packard Inn.