Iturup island of the South Kuril Islands (Chishima).Pictured:Geothermal station Okeanskaya at the foot of Baransky volkano of Iturup island. Iturup (Ainu: エトゥオロプシリ ; Japanese: 択捉島 ) is the largest island of the South Kuril Islands. It is the northernmost island in the southern Kuril/Chishima.