If you ever find yourself in Antarctica, you might see a truly amazing — and slightly unsettling — sight. It’s a five-story waterfall that gushes from a fissure in the Taylor Glacier, spilling down the rocky shore and into Antarctica’s Lake Bonney. Sounds picturesque, no?

Well, it’s certainly memorable…

Uh, you okay, Antarctica?

Aptly named Blood Falls, this waterfall pours bright red water right out of the stark, white glacier. Its shocking color and gory appearance are frightening, but of course, this isn’t really blood. Like blood, though, its red color does come from iron.

The liquid at Blood Falls is actually iron-rich, hypersaline water that leaks out from a salt lake underneath the glacier. The salt lake is actually ancient seawater left over from the Miocene Period.

Taylor Glacier covers ancient seawater that got trapped there as the icy mass formed about two million years ago. The ice of the glacier and the water of the subglacial lake are not the same water, and have drastically different properties.
The falls were first discovered in 1911 by explorer Griffith Taylor, for whom the glacier is named.

When the iron in the water hits the air, it oxidizes and essentially rusts. This is what lends the water the blood-red color you see spilling down the glacier. The fact that it does spill over occasionally is great for researchers (despite looking a bit ominous), because it lets them study the ancient water without having to drill into the glacier to get to it.

Over the years, they’ve found that the super-salty, super-cold lake is home to about 17 different types of microorganisms, which have lived there for millennia without light or oxygen. This gives scientists an idea of how life originated on this planet, and how it might survive on others.