Ousteri Lake, also known as Osudu Lake or Osudu Keri, is a significant freshwater lake located in the Union Territory of Puducherry (Pondicherry), India. Ousteri Lake is situated about 10 kilometers from the city center of Puducherry. It has a substantial catchment area, which plays a crucial role in maintaining the lake’s water levels. Ousteri Lake is recognized as one of the important wetlands in the region and is crucial for biodiversity conservation. During the migratory season, especially in winter, the lake attracts a variety of bird species, including ducks, waders, and other waterfowl.