Original: Cocky Flies , Geoscience Australia Discovered in the mid-19th century , they have been territories of Australia since 1947 , and contain the only two active volcanoes in Australian territory , one of which , Mawson Peak , is the highest Australian mountain .
Simplified: They have been territories of Australia since 1947 , and contain the only two active volcanoes in Australian territory , one of which , Mawson Peak , is the highest Australian mountain .