The Antarctic Peninsula is almost a mirror image of southern South America. In fact, it's a geologic extension of the Andes mountain range; an underwater ridge looping through South Georgia and the South Sandwich Islands connects the two features. It is claimed by Chile, Argentina, and the United Kingdom, with the United States and Russia both reserving the right to stake a claim should the Antarctic Treaty ever fall out of force. Under the provisions of the treaty, international access to the territory is permitted.