Fort Knox State Historic Site is located in Prospect, Maine, and features a well-preserved 19th-century fort. Built between 1844 and 1869, it was designed to protect the Penobscot River and the nearby city of Bangor from potential naval attacks. The fort is named after Henry Knox, the first United States Secretary of War. Visitors to Fort Knox can explore its impressive stone walls, tunnels, and historic structures. The site also offers scenic views of the Penobscot Narrows Bridge and the surrounding landscape. It serves as a popular destination for history enthusiasts and families alike, providing educational programs and guided tours.