Binnenalster

Binnenalster
Inner Alster
The emblematic Jungfernstieg and Rathaus in the background
Location	Hamburg
Coordinates	53°33′18″N 9°59′42″E / 53.55500°N 9.99500°E / 53.55500; 9.99500Coordinates: 53°33′18″N 9°59′42″E / 53.55500°N 9.99500°E / 53.55500; 9.99500
Type	artificial lake
Primary inflows	Alster (Außenalster)
Primary outflows	Alster (Kleine Alster)
Basin countries	Germany
Surface area	0.2 km2 (20 ha)
Average depth	2.0 m (6.6 ft)
Max. depth	3.0 m (9.8 ft)

Binnenalster or Inner Alster Lake is one of two artificial lakes within the city limits of Hamburg, Germany, which are formed by the river Alster (the other being the Außenalster). The main annual festival is the Alstervergnügen.

The lake has an area of 0.2 square kilometres (2,200,000 sq ft).

The phrase "inner" refers to the old city walls of Hamburg. The Binnenalster was the part of the lake that was "inside" the city walls. The lake was originally created to serve as a reservoir for a mill. As of 2008 the old city walls do not exist, instead two car and train bridges, the Lombardsbrücke and the Kennedybrücke, span the river.

The Binnenalster is bordered by embankment streets on three sides, only the northern side is bordered by a park. Jungfernstieg – on the southern side, opposite this park is a busy boulevard and center of the Binnenalster. Left and right, Ballindamm and Neuer Jungfernstieg accommodate a number of corporate headquarters and first class hotels.

The Alstervergnügen (English: Alster enjoyment) is an annual street fair held around the lake. It always takes place throughout the first weekend of September, and offers a wide variety of food, drink, vending and games stands, as well as some rock bands.