Lake Leśnia (Polish Jezioro Leśniańskie, German Marklissa-Talsperre) is a small artificial lake, located on the Kwisa river, between towns of Leśna and Gryfow Slaski in Lower Silesian Voivodeship, southwestern Poland. It was opened on July 15, 1905, after a dam had been completed near the village of Czocha. The dam was constructed between 1901 - 1905, by the government of Kingdom of Prussia’s Province of Silesia. Most workers employed during construction came from Austria and Italy, and total cost was estimated at 1,270,00 reichsmarks.