Poles actually don't use word "kraj" (which, BTW means more "country" than "land" - "land" is closer to ziemia) in their geographical names. The Southern Land in Polish would be... Południsko, Południowo or better Południna. Also, I think that if Australia was discovered by the Poles in XVIIth or XVIIIth century it might have been called Nova Sarmatia, Antiboreia or Austeria (Poles were big on classic mythology).Or how do you combine the word Południe and kraj (both are Polish words, mean "South" and "Land" respectively) into a proper enough name ?
The Dutch had another name for Australia. They called it Nieuw Holland.
Necromancy.
I'm not really aware of a lot of Greek myths about the South or Desserts. Though off I had to pick I would chose Atlas, or Maybera Atlasia.
My favorite name is either Terras Austrailasia or Antipondus, literally Anti-Weight