When many people think of lakes, they think of grayish-blue or grayish-green bodies of water - and that does describe the majority - but there are exceptions to that relatively drab rule. Colored bodies of water like Lake Hillier, Lake Pukaki, Lake Retba, Laguna Colorada, and Blood Falls can be pink, red, neon green, cyan blue, and even rainbow-colored. These wild colors aren't a fever dream - they're a very real natural phenomenon often caused by bacteria, sulfur, or algae.
Some of these lakes are safe to swim in, and others are too dangerous to get anywhere near - but all of them are visually stunning.
Where It's Located: Jiuzhaigou National Park, China
Why It's Unusual: Nestled in the valley of the Tibetan Plateau is Jiuzhaigou National Park, a UNESCO World Heritage Site. Among the loveliest natural wonders in the park is Five Flower Lake. The lake has two unique properties: It changes color and it doesn't freeze in the winter. At any given moment, the water could appear amber yellow, emerald green, dark jade or light turquoise. It might also be ringed with coral. The reasoning for this seems to be the lime, calcium carbonate, and multicolored hydrophytes that are contained within the lake.
As for its perpetually unfrozen state, that's because of an underwater hot spring that runs through the lake. Despite the scientific explanation, many of the local residents believe that the lake is holy.
Where It's Located: Yellowstone National Park, Wyoming
Why It's Unusual: The Grand Prismatic Spring is one of the many incredible sights you'll see when you travel to Yellowstone National Park. It's not a lake - actually it's a geyser that's 121 feet deep and has a diameter of 370 feet. In fact, it's so wide and so deep that when a person illegally flew a drone into the geyser, it was never seen again.
Its water, which is a brilliant blue, is ringed with bands of orange, yellow, and green. These layers exist thanks to thermophilic bacteria that live in the varying temperatures of different parts of the water. The middle is blue thanks to the scattering of blue light wavelengths.
Where It's Located: Arusha Region, Tanzania
Why It's Unusual: Lake Natron's brilliant red color might make it appear enticing, but it's one of the most dangerous bodies of water on the planet. As a salt lake, water flows into it but not out. When the water escapes through evaporation, it leaves a dense concotion of salt and other minerals. While some salt lakes like the Dead Sea are safe to swim in, Lake Natron is not. It's highly alkaline thanks to its high concentration of its namesake mineral, natron. Its pH level is 10.5 - about as high as ammonia. It's also extremely hot - the lake's temperature can climb to 140 degrees. The bacteria that thrive in this caustic environment, cyanobacteria, produce a pink pigment that creates the lake's strange color.
For this reason, hardly anything lives in the lake aside from a fish called Alcolapia latilabris, algae, and a colony of flamingos that feed on the algae. Unfortunately, the lake's shining surface causes birds and other animals to unwittingly enter the lake, a mistake that literally turns them into calcified statues. When the water recedes, the stone animals wash up on the shore.
Where It's Located: Goldfields-Esperance, Western Australia
Why It's Unusual: Lake Hillier is a striking pink color that contrasts dramatically with the nearby Pacific Ocean. It was first discovered in 1802, but the reason for its pink hue wasn't discovered until later - in fact, it's not even fully understood now.
Most scientists studying the lake think it has something to do with the Dunaliella salina algae, which produce carotenoids, a pigment that's also present in carrots. However, some think the color might be thanks to the halophilic bacteria found in salt crusts, or a reaction between the salt and the sodium bicarbonate in the lake.
Despite the extremely high salt content of the lake, it's safe to swim in.