Around 71% of the Earth’s surface is covered in water. Considering how many oceans, lakes, and rivers there are, it is only natural that a few weird or even dangerous ones will be considered absolutely off-limits. While some of these water bodies look beautiful, others are absolutely terrifying. Here is our list of the 10 most dangerous waters you will never want to swim in.

1 Lake Natron

Tanzania’s Lake Natron is straight-up nightmarish!

The water that flows into the lake cannot flow out, and as the water evaporates, it leaves behind a high concentration of salt and other minerals, turning it into a salt lake.

The lake is extremely alkaline. It contains high amounts of a chemical called natron, which is a combination of baking soda and sodium carbonate. Because of this, the water’s pH level can be as high as 10.5.
Few creatures can survive the harsh waters of the lake. Birds and other animals that are unfortunate enough to die in the lake get calcified, and their chemically-preserved carcasses remain that way forever! (1,2)

2 Boiling Lake

As the name suggests, the Boiling Lake, situated on the island of Dominica, is not ideal for swimming!

The “lake” is actually a flooded fumarole, which is basically an opening in the Earth’s crust. Around 200 to 250 feet across, it is the second-largest hot lake in the world!

Though the temperature fluctuates, the water can get as hot as 180 to 197 ℉ along the edges, and 212 ℉ is the boiling point of water.

It tends to be much hotter at the center where the grayish-blue water actively boils and bubbles, enveloping the entire lake in a cloud of vapor.

In 1900, two people died at the lake after choking on a sudden release of volcanic gases and falling to their deaths. (1,2)

3 Lake Nyos

Lake Nyos, a lake formed on top of a volcanic crater in northwest Cameroon, was responsible for one of the deadliest natural disasters in human history.

On 21 August 1986, a limnic eruption caused Lake Nyos to suddenly release approximately 1.6 million tons of carbon dioxide. Being heavier than air, the large cloud of CO2 descended onto nearby villages, suffocating and killing all life forms within a 16-mile radius of the lake. Over 1,746 people and 3,500 livestock perished.

A pocket of magma lies underneath Lake Nyos and releases carbon dioxide into the water, turning it into carbonic acid. (1,2)

4 Rio Tinto River

The Río Tinto River in Spain is famous for its unique red and orange color.

The area around the river has been a source of ore mining for approximately 5,000 years. Acid mine drainage has caused the river to become so acidic that heavy metals, such as iron, dissolve into the water, giving it the strange hue.

The unique chemical makeup of the water has made this river a harsh environment for life. Due to a pH level of around 2, only some hearty microorganisms, popularly known as extremophiles, can thrive here. (1,2)

5 Lake Hillier

Situated on the edge of Middle Island off the coast of Western Australia, Lake Hillier is a salt lake most noted for its vibrant, bubblegum-pink color.

The unique color of the water is permanent and does not change even when you put it in a container. Experts think the color is caused by an organism called Dunaliella salina, which is a green microalga. Metagenomic analysis has also revealed the presence of different species of bacteria.

Despite the high salt content, Lake Hillier is safe to swim in. However, doing so is prohibited for conservation reasons. The best way to enjoy the lake is by seeing it from the air. (1,2)

6 Monte Neme

On the El Monte Neme mountain of Spain, there is a lake filled with pristine, turquoise water. The surreal beauty of the lake has attracted many social media influencers who came here to get the perfect photo.

However, those who took a dip in the lake ended up getting very sick. They experienced hives and vomiting, among many other symptoms.

As it turns out, since 1915, Mount Neme was heavily exploited for its tungsten and tin reserves. Mining continued until 2012, when the mines were finally abandoned.

Decades of mining produced so much toxic waste that the nearby area, including the lake, became a dumping ground, making the water hazardous for swimmers. (1,2)

7 Kawah Ijen Acid Lake

In the crater of the Kawah Ijen volcano in Java, Indonesia, there is a 0.62-mile-wide lake filled with turquoise water. Though the serene lake looks inviting, swimming in it would be a mistake! It is the largest acidic crater lake in the world!

In 2008, an explorer took a small rubber boat out onto the lake to measure its acidity. The pH level of the water at the edge of the lake measured around 0.5, while at the center of the lake, the pH level was 0.13 due to the presence of a high concentration of sulfuric acid.

At the edge of the lake, there is also an active vent, which is a source of elemental sulfur, and mining continues to this day. (1,2)

8 Shark Alley

“Shark Alley” refers to a narrow stretch of water between Geyser Rock and Dyer Island near Gansbaai in South Africa. As the name suggests, this area of water is notorious for great white sharks.

During the South African winter, which lasts from April to September, a large colony of 60,000 Cape fur seals migrates to the island. The sharks are drawn to the seals and come here to hunt.

Though the site is famous for shark-cage diving, swimming outside of the cage or freediving is not permitted. (1,2)

9 Berkeley Pit

The Berkeley Pit, a former open-pit copper mine, is located in Montana in the United States. Approximately 1,780 feet deep, the pit is filled with heavily acidic water. Dangerous chemicals and heavy metals leach from the surrounding rocks making the water even more hazardous.

In 2016, several thousand snow geese landed on the water to avoid a snowstorm and ended up dying. After this, officials made active efforts to scare away birds to prevent them from landing on the toxic water.

The site has become a popular tourist attraction, and visitors have to pay $2 to be allowed on the viewing platform. There is also a gift shop adjacent to it. (1,2,3)

10 Amazon basin

The Amazon basin covers an area of 2,400,000 square miles. Most of the basin is covered by a dense tropical forest that we all know as the Amazon rainforest.

Needless to say, the Amazon basin is home to one of the most diverse collections of wildlife. From birds and reptiles to mammals and amphibians, all life forms exist here, and many of them are extremely dangerous.

The black caiman, found in the flooded savannas of the basin, are large crocodiles that grow up to 14 feet long and weigh up to 1,100 lbs.

The area is also home to piranhas, anacondas, candiru, and many other dangerous creatures. (1,2)

What are some other dangerous waters that we should know about? Let us know in the comments!