Summer, Spring, Fall: Maine is home to its own Fort Knox, located in Prospect along the Penobscot River. The fort was built in 1844 orinally to protect the state from a British Naval invasion. During the American Revolution it was utilized as a cannon battery. The fort is a great historical treasure that can be explored by the whole family. There is now an observatory at the top of the newly constructed Penobscot Narrows Bridge in which can be accessed through the fort. It rises 420 ft. above sea level and provided visitors with unbelievable views of the whole fort as well as the river valley. Bring a picnic lunch with you or make this a stop on your way up to Bar Harbor. The Fort is open from May to November, sun up to sun set. It is a great way to experience Maine’s rich history.