Fort Knox and the Penobscot Narrows Observatory is situated in Prospect, Maine right beside the Penobscot River.
The well-preserved historical military base was a primary site of many a border disputes between the U.S. and British controlled Canada. In fact, Fort Knox was first built for the very purpose of guarding against any British attacks from that direction. Construction began in 1844 and didn't end till 1869. Led by Chief Engineer Joseph Totten, a team of engineers supervised the construction work.
Before its final completion, the fort was named for Major General Henry Knox, the first U.S. Secretary of War in the 1700s. It was also banned before it was completely finished. Its first military personnel included volunteers who were trained there and soldiers from the 20th Maine. Fort Knox was last manned for war in 1898 during the Spanish American. However, it never in its existence saw a day of actual battle. After the Spanish American war, it was tended by one man who made sure everything was kept in tip-top shape.
The fort was tended until 1923 when the U.S government decided they didn't need it and put the fort’s property up for sale. It was purchased by the State of Maine and made a historical site in 1970. It maintains this status today and welcomes visitors to its extremely well-preserved fort. The fort also offers access to the observation tower of the nearby Penobscot Narrows Bridge. Both Fort Knox and the Penobscot Narrows Bridge Observatory are open to the public from May 1 to October 31. Fort Knox and the Observatory are so close that one admission ticket gives visitors access to both.