The water reservoir Janov or the Mostecká dam, is a building from 1911-1913. The dam is 44.5 meters high and 225 meters long. It lies northwest of Litvínov and serves as a drinking water supply for the city of Most. The public is inaccessible, but there is a red tourist sign from the Litvínov Railway Station around the dam, continuing to lookout tower Jeřabina.