A long narrow island belonging to Russia, situated close to the E. coast of Siberia, from which it is separated by the so-called Gulf of Tartary; stretches N. from the island of Yezo, a distance of 670 m.; is mountainous and forest-clad in the interior; has excellent coast fisheries, but a cold, damp climate prevents successful agriculture; rich coal-mines exist, and are wrought by 4000 or 5000 convicts. Ceded by Japan to Russia in 1875.