Außenalster

or Outer Alster Lake is the larger one of two artificial lakes, which are formed by the Alster River and are both located within the city limits of Hamburg, Germany. The other lake is the Binnenalster. The Außenalster and its shores are used by the inhabitants of Hamburg for many sport and recreational purposes, such as sailing and rowing.OverviewHistoryThe phrase "outer" refers to the former Wallanlagen (city walls) of Hamburg. The Außenalster was the part of the lake that was "outside" the city walls, built in 1625. In 1804 city wall and ramparts were stripped down and re-naturalized to parks, but the spatial division between the two lakes was retained. Today, two car and rail bridges, the Lombardsbrücke and the Kennedybrücke, span the river at this location. The areas around the Außenalster developed slightly different on the eastern and western sides; while the western side became a wealthy suburban area around the late 18th century, much of the eastern side used to be a property of the finance department of the City of Hamburg and only developed in the later decades of the 19th century.GeographyThe Außenalster has a size of 1.64km2 and is on average only some 2.5m deep. It is fed by the rivers Alster, Osterbek (via Osterbekkanal) and Wandse (via Mundsburger Kanal). Other canals entering the Außenalster include Rondeelkanal, Goldbekkanal and Uhlenhorster Kanal. The lake also forms a number of smaller bays and inlets. The Alster River enters the Außenalster in the North at Krugkoppelbrücke and leaves it in the South at Kennedybrücke.