Fort Foster located in Kittery Maine is one of my favorite places to visit. The fort was built around 1897 and was primarily used as costal defense. The pier stretches out into the Piscataqua River close to Woods Island rescue station where they used to use wooden row boats to rescue stranded ships caught on the many rocks in the area. From the pier you can see the Portsmouth Naval Shipyard where they used to build submarines and now repairs and overhauls them. You also have a close-up view of the cribworks that used to block small craft from entering the river at high tide during World War II.
You can also see the old Naval prison on the shipyard, the prison was occupied from 1908 right up to 1974.