Indeed, since it's where we started throwing off the yoke of our British oppressors. ;-) Actually, if you walk Battle Road (which is a lovely path through woods and open land past some preserved colonial homes) there are little Union Jacks marking the spots where British soldiers fell.

The Colonial Inn on the roundabout in Concord center has a nice historic feel (haven't been in ages to speak about the food). There are other decent restaurants in town. The train station is a block or two from the actual center. There's a good coffee shop (aside from Nero) called Haute Coffee on a back street. On the way to Battle Road is First Parish (pretty sure Emerson and Thoreau went there), the Concord Museum, one of Hawthorne's homes, and the Alcott home (associated with Little Women). If you don't feel like the full Battle Road walk (it's a mile or so to the start, and then ~11 miles, I think?), you can also walk up to Old North Bridge, very pretty, site of another battle. There are some other trails that lead to Great Meadow. If it's cold, you'll want places to duck into and warm up. For the Christmas break, the visitor's center at Old North Bridge might be open.