6.Lake Hillier, Australia

Viewed from above, Australia’s Lake Hillier appears to be covered with Pepto Bismal. It’s bright pink. The hue comes from the same algae that lives in San Francisco’s salt ponds: the salt-loving Dunaliella bacterium. It contains pigment components that make it exceptionally effective at absorbing sunlight, resulting in the reddish-pink hue.

Scientists discovered a combination of algae and bacteria that contributed to Lake Hillier’s pink tint. The lake’s coloration can be attributed to the presence of microbes from a leather tanning facility in the early 1900s.

So, this example is half natural and half man-made; the lake’s hue is very bright as a result of human activity.