Novosibirsk Reservoir or Novosibirskoye Reservoir, informally called the Ob Sea, is the largest artificial lake in Novosibirsk Oblast and Altai Krai created by a dam on the Ob River near Novosibirsk. The dam, built in 1956, is for generating hydroelectric power. The reservoir is 160 km long and up to 20 km wide. The power of hydroelectric power is 400 MW. During the summer, it is one of the most popular destinations for Novosibirsk residents with many yachts and boats dotting the surface of the lake, and the beaches teeming with people.
Novosibirsk region is a part of Siberian federal district of Russian Federation. It's located in south-west Siberia and adjacent to the Republic of Kazakhstan and Russia's Altai region. Its administrative and economic center is the city of Novosibirsk.