One of the weirdest places in Antarctica is Blood Falls, a five-story cascade of blood-red liquid pouring from Taylor Glacier. Researchers finally traced its source: a saltwater lake millions of years old trapped under the glacier.
Over time, the salt oxidized iron in the lake's bed, because the lake remained liquid despite being underneath the ice.
In the image by Peter Rejcek above, there's a tent in the left foreground for scale. When the Falls were first discovered, it was assumed they were caused by algae. Among the interesting findings since then is that living microbes are trapped in the brine lake that feeds Blood Falls.
Here's a helpful video from Atlas Obscura:
• An englacial hydrologic system of brine within a cold glacier: Blood Falls, McMurdo Dry Valleys, Antarctica (via TreeHugger)