
1) Disputed island 2) Island of the Kuril Islands 3) Island of the Sea of Okhotsk
Found on
https://www.crosswordclues.com/clue/iturup

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. The strait between Iturup and Urup is known as the Vries Strait, after Dutch explorer Maarten Gerrit...
Found on
http://en.wikipedia.org/wiki/Iturup
No exact match found.