My Intrepid Starforting Sister and I stayed at the Fort Knox Park Inn (the obvious choice) in Bucksport, across the Penobscot from the fort itself. Upon arrival I immediately upgraded the room to one with a fort view, because, duh. Visible to the left of the fort is the Penobscot Narrows Bridge, atop the right span of which is the Penobscot Narrows Observatory.