Onekotan is an uninhabited volcanic island located near the northern end of the Kuril Islands chain in the Sea of Okhotsk in the northwest Pacific Ocean. Its name is derived from the Ainu language for "large village”. It is the second largest island, after Paramushir, in the northern subgroup of the Kurils. It is administratively included in the Severo-Kurilsky District of Sakhalin oblast, Russia.

Paramushir is a volcanic island in the northern portion of the Kuril Islands chain in the Sea of Okhotsk in the northwest Pacific Ocean. It is separated from Shumshu by the very narrow Second Kuril Strait in the northeast 2.5 km (1.6 mi), from Antsiferov by the Luzhin Strait to the southwest, from Atlasov in the northwest by 20 km (12 mi), and from Onekotan in the south by the 40 km (25 mi) wide Fourth Kuril Strait. Its northern tip is 39 km (24 mi) from Cape Lopatka at the southern tip of the Kamchatka Peninsula. Its name is derived from the Ainu language, from “broad island” or “populous island”. Severo-Kurilsk, the administrative center of the Severo-Kurilsky district, is the only permanently populated settlement on Paramushir island.