Submarine D-2 (Narodovolets until 1934) is one of the first Submarines built in Soviet period. It was put into service in 1931. It is a historical memorial of Russian Navy and Submarine building. The submarine participated in the World War II (1939-1945). From 1956 till 1987 D-2 was used as a training station for survival practice. At the end of 1980s - beginning of 1990s submarine had been repaired by Baltic Shipyard. Exteriors and interiors of the submarine were restored as they were during the war. The branch of the Central Naval Museum was established on September 2, 1994. The memorial complex is a unique one in Russia and meets serious interest of visitors.