Queensland has become one of the most deadly places to swim. It is because of one obvious reason: it has a lot of deadly and terrifying creatures. So, going there for a swim would probably be your last mistake. The Queensland is home to some of the really terrifying sea creatures that include sharks, saltwater crocodiles, stonefish, and the exceptionally deadly blue-ringed octopi and box jellyfish. One sting from the box jellyfish can kill you within minutes.