Concord is a town in Massachusetts. One of the first battles of the American Revolution was fought here at the Old North Bridge. Henry David Thoreau penned Walden here. The home town of Ralph Waldo Emerson and Louisa May Alcott.
Traveling by car is easiest, but many of the tourist attractions are within walking distance of each other. Liberty Ride is a seasonal trolley between Lexington and Concord that serves many of the tourist attractions.
For more history it's Lexington or Boston. North Shore towns have the closest beaches. The White Mountains are great for hiking, fall foliage viewing or skiing.