Australia's Ancients V
The Saltwater Crocodile is one of the most dominant predators of the world. Those precious few that survive the difficult youth stages become an apex predator with little to fear. Fewer still will control a territory to do with as they please. Humans should avoid even the most inviting waters in Queensland due to the secretive and lethal nature of the crocodile.
Locals in Queensland constantly preach the following to tourists: "If you don't know, don't go!"
Only freshwater bodies at high enough altitudes with cold enough temperatures are free from croc habitation.