Original: Belief in the existence of a Terra Australis â '' a vast continent in the far south of the globe to '' balance '' the northern lands of Europe , Asia and North Africa â '' has existed since the times of Ptolemy ( 1st century AD ) , who suggested the idea to preserve the symmetry of all known landmasses in the world .
Simplified: They thought this Terra Australis would '' balance '' the lands in the north like Europe , Asia and North Africa . People have believed this from the times of Ptolemy ( 1st century AD ) .