Ogosta (Bulgarian: Язовир Огоста) is a lake in the North West of Bulgaria. It is the second largest artificial lake in Bulgaria and The Balkan Peninsula and one of the biggest in Europe. It collects the waters of the rivers Ogosta, Burzia and Zlatitsa and is located about 600 meters to the south-west of the border of Montana city and 60 m. above the level of the city. The water collecting basin is with area of 948 km2 and the area of the lake itself is 24 hectares. The average water volume is 384 Mm3 and the overall volume 506Mm3.