The Adelaide River is home to the highest concentration of giant saltwater crocodiles in the world, as well as the highest concentration of aggressive bull sharks in the world. There are rarely attacks on people here, mostly because locals know to steer clear from going into the water, but every once in a while someone disappears into the murky depths.
Hanakapiai Beach
Hanakapiai Beach in Hawaii is the most dangerous place to swim in the world. This beach has a constant rip current that naturally occurs because it is such an aggressive inlet. There are sharp rocks under the enormous waves that break directly on the shore, and those who can even make it off the beach are most likely going to get swept so far into the current that they won’t be able to make it back to shore before they become exhausted from treading water.