Iturup (Russian: Итуру́п and Oстров Итуру́п, Ostrov Iturup; Ainu: エトゥヲロㇷ゚シㇼ, Etuworop-sir; Japanese: 択捉島, Etorofu-tō) is the largest island of the South Kuril Islands. It is the northernmost island in the southern Kuril/Chishima islands, and though it is controlled by Russia, Japan also claims this island (see Kuril Islands dispute). It was Japanese territory until the end of the Second World War, but Japanese residents were forced out following the Soviet invasion in 1945.
Iturup is located near the southern end of the Kuril/Chishima chain, between Kunashiri (19 km to the SW) and Urup (37 km to the NE). The town of Kurilsk, administrative center of Kurilsky District, is located roughly midway along its western shore.
Area – 3,139 km²
Length – 200 km
Width – 7–27 km
The strait between Iturup and Urup is known as the Vries Strait, after Dutch explorer Maarten Gerritsz Vries, the first recorded European to explore the area.