Answer: Australia
Notes: The Heard and McDonald Islands are located in the sub-Antarctic region and serve as external territories of Australia. These volcanic islands, discovered in the 1850s by American mariners John Heard and William McDonald, were proclaimed as a UNESCO World Heritage site in 1997. These islands, recognized for their unique wildlife and geology (including active volcanoes), are considered one of the world's most remote places. Initially claimed by the UK in 1910, they were transferred to Australia in 1947, hence, the land boasting the highest mountain under Australian sovereignty.
