Lexington & Concord are historic sites not to be missed: Lexington has the beautiful green with the Minute Man statue, along with many very old historic buildings and taverns where the Revolution was planned and launched. It is easy to tour the entire Lexington green, all in one place. There is a "trolley bus" that goes around Lexington and Concord, a 90 min trip several times a day, that takes one to all the major sites. I went there a few weeks ago during a weekday, and there were not huge crowds, just a few families. Lexington is an awesome historic place, and very close to Boston itself - it is right outside Boston. Despite the daily Boston traffic, it is well worth traveling out to Lexington for a day of fun and history! You will be glad you did, Lexington's country setting is quite a contrast to Boston's urban setting, it will be a peaceful exhilarating contrast to 'round out' your trip. There is no need to make reservations if you go during the week, just head out there and Enjoy!!
https://www.tourlexington.us/