However, the Habomai Islands, together with Iturup, Kunashir and Shikotan, are claimed by Japan.
The island got its name from the Russian explorer and geographer Aleksandr Semyonovich Polonsky [ru].
The island has an area of 12 km2, is flat, with a maximum height of 16 metres (52 ft); it is green and marshy.
Its waters are rich in fish, particularly some species of salmon, cod and crabs and it is part of the territory of the Kurils Nature Reserve.
[1] Polonsky Island is separated from Shikotan by the Spanberg Strait, to the southeast are the Oskolki islets.