(Nadezhdinskii mine until 1925), an urban-type settlement in Irkutsk Oblast, RSFSR. It is situated on the Bodaibo River, a tributary of the Vitim. In 1968 the population was 1,200. Gold is mined in the area. Aprel’sk was the site of the Lena execution of workers by firing squad on April 4 (17), 1912; a monument to the victims was raised there in 1967.