At Minute Man National Historical Park, the Battle Road Trail follows the British retreat from Lexington and Concord, out to the Old North Bridge over the Concord River. On the same Route 2 corridor, Walden Pond's shoreline holds the replica of Thoreau's cabin. You spend the night under the pines at Pearl Hill State Park, or next door at Willard Brook State Forest.
Minute Man is free, and the grounds, trails, and parking areas stay open daily sunrise to sunset. Concord is the town between the park and Walden Pond. The Route 2 day runs through the battlefield, the town, and the pond in that order, one westbound road rather than three separate trips from Cambridge. Walden Pond has no camping, and the parking lot closes once it fills on summer days, so start that stretch in the morning.
Cambridge has no campground of its own, so the overnight is west on Route 2. Pearl Hill puts you under a pine canopy on primitive sites, a bathhouse with showers. The loops are tents and small rigs by design, more than 50 sites with no hookups. Willard Brook State Forest is the overflow in the same woods when Pearl Hill is full, restrooms only, no showers posted.
Massachusetts DCR runs Pearl Hill's campground Memorial Day weekend through Labor Day weekend. Both campgrounds book through ReserveAmerica on a four-month window, and you lock the site before you book the van. If you need more sleeping space than a campervan holds, start with RVs for rent in Cambridge.
The Friends Trail is a four-mile loop between Willard Brook and Pearl Hill, at least a three-hour walk. Park at either campground and you can reach the other on foot.
Fruitlands Museum in Harvard
West on Route 2 in Harvard, the 1820s farmhouse at Fruitlands Museum looks over the Nashua River Valley toward Mount Wachusett. It is a Trustees of Reservations hilltop on the same road as Concord. The museum keeps timed hours from late April through early November and is a day stop only, with no overnight on the grounds. Back in Cambridge, the Charles River is non-motorized boats and a paved path along the water.
Salem's October and the Patriots, Marathon, and Red Sox weeks are on the Boston campervan page. Harold Parker State Forest is the overnight on the Andover campervan page. The Berkshires and the rest of Massachusetts are on Massachusetts campervan rentals.