Aasee is a lake at Münster, North Rhine-Westphalia, Germany. At an elevation of 54 m, its surface area is 0.402 km2. During the siege of Münster by Prince Bishop Christoph Bernhard von Galen on December 18, 1660, two earth walls were broken with which the city had been cut off from the water supply, thus causing much of the city area to be flooded. [2] Munster later surrendered to the besiegers. The bodies of water from the dam rupture could still be seen years later at the site of present-day Lake Aa. Until the beginning of the 19th century there were wetlands and marshy meadows through which the Aa flowed. These meadows were regularly flooded, and the water level sometimes reached such proportions that the old town of Münster was flooded. The Münster professor of zoology, Hermann Landois, spoke in 1888 in favor of the construction of an "Aa basin" not only to be able to better control the water level of the Aa. [1] At the same time, Landois wanted to use the reservoir to ensure the city's drinking water supply, to allow sports activities such as rowing, sailing and swimming, to contribute to the beautification of the city, but also to reduce the source of pathogens from a hygienic point of view was used by flushing the Aabett, as the Aa also acts as a city sewer. [3] It was not until a quarter of a century after Landois' first statements and nine years after his death, in the spring of 1914, that Italian workers began to implement their vision to reduce the risk of flooding in the city of Münster. However, the excavation of the artificially created Aasee was interrupted by the outbreak of the First World War in the same year. The work only continued after a severe flood in 1925 during the tenure of Mayor Georg Sperlich. Finally the lake was completed in 1934 with a water surface of 20.7 hectares.

In general its an good place to enjoy with your family or friends.