largest island in russia
Sakhalin is the largest island in Russia, being 948 km (589 mi) long, and 25 to 170 km (16 to 106 mi) wide, with an area of 72,492 km 2 (27,989 sq mi). Its orography and geological structure are imperfectly known. One theory is that Sakhalin arose from the Sakhalin island arc.