If you were there to see Plymouth Rock under renovation all you had to do was turn around to see the Mayflower, it's 500 feet away! And how do you renovate a rock, anyways? It's a freakin' rock.
If you have time, take a drive out to Charlemont and go rafting on the Deerfield River. It's not the Colorado but shooting Zoar Gap is fun and in September the water is warm. Then drive thru the Berkshires, my favorite towns are Peru and Beckett. Gorgeous. Hike up Mt Greylock, the highest point in Mass. Herman Melville looked out upon it's snow covered shoulders as he wrote Moby Dick. Take the ferry to Marthas Vineyard or Nantucket. Nantucket is much cooler but further away, although both have good local brews, Offshore Brewery on MV and Cisco on Nantucket. I like Cisco's brews more. Hike thru the Blue Hills Reservation and climb The Great Blue Hill, home of the oldest continious weather station in the US, also home of the original broadcast tower for the original public television station WGBH (Great Blue Hill). Norm Abrams and Julia Childs won't be up there waiting for you, sorry. (Ok Norm might but Julias dead.) I think the Boston Pops are back in the city by September but check into Tanglewood in Lenox just to be sure, a symphony orchestra plays while you picnic on lawn chairs. Old Sturbridge Village in Sturbridge MA is like Colonial Williamsburg in VA, just smaller. Plum Island in Newburryport or teh Cape Cod National seashore are world class beaches. You are more likely to see seals on the Cape while PI is a bird watchers paradise.
PTN