From a crack in the Taylor Glacier in Antarctica flows an iron-rich water the color of blood. Scientists believe it comes from a lake frozen beneath the glacier 2 million years ago. And it's packed with microbes.
First discovered in 1911, the so-called Blood Falls also contain extremophile microbes from the trapped lake, which have evolved for millions of years without light or any outside food source. They have survived by learning to eat sulfur and iron.
According to Atlas Obscura:
Roughly 2 million years ago, the Taylor Glacier sealed beneath it a small body of water which contained an ancient community of microbes. Trapped below a thick layer of ice, they have remained there ever since, isolated inside a natural time capsule. Evolving independently of the rest of the living world, these microbes exist without heat, light, or oxygen, and are essentially the definition of "primordial ooze." The trapped lake has very high salinity and is rich in iron, which gives the waterfall its red color. A fissure in the glacier allows the subglacial lake to flow out, forming the falls without contaminating the ecosystem within.
via Atlas Obscura