The submarine B-413 of Project 641 (Foxtrot by NATO classification) is a unique museum vessel. It is the only submarine in the country and one of the few in the world that belongs to the pre-nuclear period of the submarine fleet. The submarine is also unique in that it has been preserved in its original form. The strong and light hull, superstructure, all main and auxiliary mechanisms, instruments and weapons are presented to visitors in the same form as on the day the ship was decommissioned from the Russian Navy. Ocean-going diesel-electric submarines of Project 641, to which the submarine B-413 belongs, were built from 1958 to 1971 at the Novo-Admiralty Shipyard in Leningrad. A total of 75 submarines were built: 58 for the USSR Navy, 17 for India, Libya and Cuba. Until the 1990s, submarines of this project carried out missions in the Atlantic, Indian and Pacific Oceans. B-413 was launched and entered service with the USSR Navy in 1968. Until 1990, the submarine was part of the Northern Fleet, and later part of the Baltic Fleet. In 2000, it was transferred to the Museum of the World Ocean. In 2018, submarine B-413 was awarded the “Maritime Heritage of Russia” sign. Today, you can see the “From the History of the Russian Submarine Fleet” exhibit on the boat.