So imagine this: You're strolling along a road in the Andes when suddenly you come across a patch of very spiky ice - spikes that hit as high as your waist, as high as your shoulders. There isn't any other snow around, just rocks and gravel... and these strange spikes of ice.
It'd be a little weird, right? These are called Penitentes (or nieves penitentes). The tall, thin spikes are typically blade-shaped and can be found at high altitudes above 13,000 feet and are made of hardened snow or ice. The blades usually are oriented toward the sun.
When Charles Darwin first described these strange formations in 1839 after seeing them near the Piuquenes Pass between Chile and Argentina, the local belief was that they are formed by the strong winds of the Andes. However, they're a bit more complicated than that.
