We happened upon Cogswell’s Grant quite by accident. The 18th Century farmhouse (yellow) holds a famous collection of American folk art. It was a brutally hot day, so we declined an offer of a guided tour, took a few, fragmentary photos, and went on our (air-conditioned) way. However, we plan to come again, to see the folk art, during one of our frequent trips to this area. This working farm and 

historic house museum are owned by Historic New England, which offers guided tours in-season.