As summer temperatures rise, so does the temptation to cool off with a refreshing dip. It’s a pretty natural thing, especially if it’s a craving to eschew chlorine-laced pools and jump into something more natural like a lake or river. However, not all bodies of water are what they seem and if you’re trekking through a foreign land, you may not know that the refreshing turquoise lake or crystal clear pond you just discovered may have some nuclear waste in it or turn animals to stone (for real, that’s a thing). Because while taking time to swim in some local waters on the road is usually a fun (and good idea), it can be tricky — you are, after all, “not from around here.”
Here are some places that should be avoided when strapping on your bathing suit during your next trip…and their safe (but still stunning) alternatives that you can dive into.
The Blue Lagoon, United Kingdom

Flickr Creative Commons – Simon Harrod
With a name like “The Blue Lagoon” you would think this is the spot to go for a swim while in Buxton, Derbyshire. However, swimming in the infamous Blue Lagoon is akin to taking a dip in a giant vat of bleach! The Blue Lagoon came into being as the old Far Hill Quarry was closed. The quarry was flooded with its surrounding limestone rocks giving the water a pretty blue color. With a pH level of 11.3, the Blue Lagoon is on a similar pH level to bleach and ammonia. In addition to harboring toxic chemicals from the surrounding rocks, the body of water boasts trash, dead animals, and excrement. While you would think no one would want to swim here, the enticing blue color still brings in swimmers who ignore the many warning signs.
Swim Here Instead: If you still want to satisfy an urge to swim in a quarry in the United Kingdom, try the Goldiggins Quarry in Minions, Cornwall. The spring fed quarry lake boasts crystal clear waters and loads of flat rock ledges making for ideal perches for big splashes and dives. Goldiggins Quarry is famous in the U.K. “wild swimming” scene and a fantastic spot for anyone wanting to try the natural swimming experience.
Lake Karachay, Russia
Set in the Ural Mountains in Russia, Lake Karachay is often deemed the most polluted place on Earth. In fact, it’s so polluted that the lake is radioactive. Lake Karachay can thank the neighboring Mayak Production Association for its deadliness. The nuclear waste storage and processing facility has been dumping nuclear material into the area’s lakes and rivers for decades. Even just standing on shore can be deadly: If a human were to hang out on Lake Karachay for an hour, they would be exposed to a lethal dose of radiation.
Swim Here Instead: Set in southeastern Siberia, you will find the oldest and deepest lake in the world, Lake Baikal. Not only is this Russian lake safe to swim in but it also boasts some of the most pure water in the world. Lake Baikal lines with resorts and towns catering to those who want to get out on the water, making it a perfect destination for anyone looking to swim in and relax along the shores of the “Pearl of Siberia.”
Lake Natron, Tanzania
If turning to stone sounds like something so impossible that it only belongs in a science fiction novel or a Game of Thrones episode, think again. Lake Natron in northern Tanzania gives the appearance of a beautiful lake. Its blood red color is due to the high levels of bacteria that inhabit it. Water temperatures can get boiling hot here, with recorded temperatures hovering around 140 degrees Fahrenheit. Lake Natron holds extremely high alkaline content, which in turn causes animals that get near it to calcify. These animals tend to look as if they’ve turned to stone after lapping up the lake’s waters. The lake’s inhabitable composition can be blamed on a neighboring volcano.
Swim Here Instead: If you don’t want to turn to stone, you can instead paddle on over to Tanzania’s famous archipelago, Zanzibar. Composed of two main islands, Zanzibar boasts countless powdery soft sands lapping up impeccably turquoise waters of the Indian Ocean, making for prime swimming conditions. It’s also a spot known for its aquatic wildlife, including reef diving, so come ready to share the water with some critters.
Citarum River, Indonesia

Flickr Creative Commons – James Chen
Swimming in a river can be a fun activity in some parts of the world. However in Indonesia, you definitely wouldn’t want to take a dip in the Citarum River. Considered one of the world’s most polluted rivers, the Citarum River sits just 40 miles east of Jakarta. It runs nearly 200 miles from the Wayang Mountain to the Java Sea. Given that over 200 textile factories have lined up on the river, dumping lead, arsenic, and mercury into its waters, the river is extremely toxic. Toss in the fact that the surface is almost always carpeted with trash and you have the makings for one of the world’s most horrifying rivers.
Swim Here Instead: The Citarum River shouldn’t turn you off of Indonesia for your swimming needs. Instead, take a dip in the Gili Islands, an archipelago off the coast of Lombok. Composed of three islands, the Gili Islands fill with white sand beaches and turquoise seas for a swimming scene that is both serene and idyllic. It’s known of as the “turtle capital of the world” and visitors have the chance to share the water (while snorkeling) with green-sea and hawksbill turtles.
[perfectpullquote align=”full” cite=”” link=”” color=”” class=”” size=””]Know of a body of water that travelers should avoid swimming in? Or have a recommendation on some foreign spots worth wading into? Share them with us in the comments below![/perfectpullquote]