Macquarie Island, a UNESCO World Heritage Site, lies in the southwest Pacific Ocean, about halfway between New Zealand and Antarctica. Since 1948 the Australian Antarctic Division (AAD) has maintained a permanent base, the Macquarie Island Station, on the isthmus at the northern end of the island at the foot of Wireless Hill. The population of the base, the island's only human inhabitants, usually varies from 20 to 40 people over the year