Thoreau observed: “We are never prepared to believe that our ancestors lifted large stones or built thick walls. How can their work be so visible and permanent and themselves so transient? When I see a stone which it must have taken many yoke of oxen to move, lying in a bank wall . . . I am curiously surprised, because it suggests an energy and force of which we have no memorials.” What started as largely invisible walls turned into a local history lesson and a set of existential questions from Thoreau,
