I'd guess the Lake Eyre internal drainage system - the Dimantina, Georgina and Coopers Ck. And that's not counting the western creeks like the Macumba and Neales.
Leichardt River, Mt Isa. It flows inwards, rather than towards the Gulf... like the other streams... My mother grew up there... she often used to say, it would be raining in the Gulf of Carpentaria, no rain around Mt Isa, then through the channel, just come down in wall.
Too obscure!!
Meteor crater.
EXPLORING HIS VAST CATTLE station in 1899, Walter Parker came upon a feature in the landscape he could not explain. A 15m-deep, bowl-shaped depression, larger than a football field, had been gouged out of the Central Australian desert. Henbury station, 115km south-west of Alice Springs.
duck, could you ask the next question please, I'm off to SA or Vic for a few weeks & may not be able to followup. Thanks Barry