Lake Anosy ("Lac Anosy" in French) is a man-made lake, also known as a reservoir, in Madagascar. It is in Antananarivo, the capital city of Madagascar. It is in southern Antananarivo and has a small island in the middle with a monument and statue on it. The monument and statue commemorate those who died during World War 1.
Lake Anosy used to be a swamp but it was replaced in 1830.