The Magdeburg Water Bridge is a navigable aqueduct in Germany that connects the Elbe-Havel Canal to the Mittelland Canal, and allows ships to cross over the Elbe River. At 918 meters, it is the longest navigable aqueduct in the world.
This bridge and tunnel goes under water to allow movement of ships. You drive down in the water and then come out on the other side. This bridge is between Sweden and Denmark. Picture taken from the side of Sweden.