Among the world’s remaining battleships, Texas is notable for being the first US battleship to become a permanent museum ship, the first battleship declared to be a US National Historic Landmark, and is the only remaining World War I–era dreadnought battleship. She is also noteworthy for being one of only seven remaining ships and the only remaining capital ship to have served in both World Wars.
…but upon reflection it was only one.
Bloede’s Dam was a hydroelectric dam on the Patapsco River in Maryland. It was the first known instance of a submerged hydroelectric plant, where the power plant was actually housed under the spillway. It is also recognized as one of the earliest dams constructed of reinforced concrete. (wikipedia)
It was demolished September 2018.