Please answer the following question: Vlasina Lake -  Vlasina Lake (Serbian: Власинско језеро Vlasinsko jezero) is a semi-artificial lake in Southeast Serbia. Lying at an altitude of 1211 metres (3973 ft) with an area of 16 square kilometres (6.2 sq mi) it is the highest and largest artificial lake in Serbia. It was created in 1947–51 when the peat bog Vlasinsko blato (Vlasina mud) was closed off by a dam and submerged by the waters of incoming rivers chiefly the Vlasina. Given a choice of categories company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, the text refers to which one?
Answer:
Natural Place