Watch: 'Firefall' at Yosemite National Park

Horsetail Fall appears the same color as lava during sunset each February.

Gary Willig,

Yosemite 'Firefall'
Yosemite 'Firefall'

A remarkable natural phenomenon causes the Horsetail Fall at Yosemite National Park in California to appear to be a fall of molten lava for ten days each February.

The phenomenon, known as a 'firefall,' can be seen when viewing the waterfall at sunset at the right angle. The water reflects the sunlight in the colors yellow, orange and red, giving it the glowing appearance of a river of lava.