This is a channel-bridge over the River Elbe and joins the former East and West Germany,
as part of the unification project.

The Magdeburg Water Bridge is a navigable aqueduct in Germany.  It connects the Elbe-Havel Canal to the Mittelland Canal, and allows ships to cross over the Elbe River.  It is the longest navigable aqueduct in the world at 918 meters. (Pics)

The Elbe-Havel and Mittelland canals had previously met near Magdeburg but on opposite sides of the Elbe. Ships moving between the two had to make a 12-kilometer detour, descending from the Mittelland Canal through the Rothensee boat lift into the Elbe, then sailing downstream on the river, before entering the Elbe-Havel Canal through Niegripp lock. Low water levels in the Elbe often prevented fully laden canal barges from making this crossing, requiring time-consuming off-loading of cargo.

Construction of the water link was started as early as in the 1930s but due to the World War 2 and subsequent division of Germany the work remained suspended till 1997. The aqueduct was finally completed and opened to the public in 2003.

Via Amusing Planet