Blood Falls

A crimson waterfall pouring from a glacier in Antarctica/Natural Wonders

Blood Falls is a five-story-tall outflow of iron-rich, hypersaline water that emerges from the tongue of Taylor Glacier in the McMurdo Dry Valleys of Antarctica. The striking red color comes from iron oxide: when the iron-rich water contacts oxygen in the air, it rusts on contact, staining the ice below a vivid blood red. The water source is a subglacial lake that has been sealed beneath 400 meters of ice for roughly 1.5 to 2 million years. Despite being extremely salty and devoid of light or oxygen, the trapped water supports microbial life, offering clues about the possibility of life on icy moons like Europa.