Civil War  |  Fort

Fort Knox State Historic Site


740 Fort Knox Road
Prospect, ME 04981
United States

Fort Knox, built to protect the Penobscot River Valley from attack, is a massive third-system defensive structure overlooking the Penobscot River that was used as a garrison for Union troops during the Civil War. The Penobscot Narrows Bridge and Observatory features a 420-foot tall observation tour overlooking the river, the only one of its kind in the western hemisphere.