Amazon Beaches, South America

Reflection of mangrove trees in Barra Velha beach, by the Amazon river mouth, in Soure, Marajo island, Brazil.Mariano Villafane/Shutterstock

You’ll find plenty of animals that pose an issue for swimmers here, such as anacondas, electric eels, piranhas, and vampire fish (candiru). Unfortunately, the area is also home to quite a bit of gang-related crime, like drug trafficking and robberies. Hundreds of small rivers make it easier for criminals to make their escape, like modern-day pirates.

Northern Territory, Australia

The beach in Arnhem land of Northern Territory state of Australia.Boyloso/Shutterstock

Australia’s poisonous wildlife isn’t limited to land species. In this far-flung corner of the continent, you’ll share the water with ravenous saltwater crocs, stonefish, jellyfish, and so much more. And the area is so isolated (most beaches don’t have names; the area is known as Arnhem Land) that any call for help may go unanswered for a long time. For more family-friendly options, these are the 20 best family beaches.

Staithes Beach, UK

Staithes, North Yorkshire, England, UK - September 07, 2016: View across the beach with some boats and peopleBerndBrueggemann/Shutterstock

Surfers might be attracted to the giant waves at Yorkshire’s Staithes Beach, but they’ll be less keen on the contents of its water. The beach repeatedly makes the EU’s “swimming prohibited” list because of all the pollutants in the area. According to the BBC, the main reason for the high pollution levels is farm sewage draining into the harbor. “Breakwaters compound the issue by keeping the water within the harbor and limiting dilution from the sea,” said Dominic Shepherd, an environmental agency water quality manager.