The 'firefall': sunlight on Yosemite waterfall creates rare illusion

For just a few days each year, the water of Horsetail fall in Yosemite national park appears like lava, drawing crowds of onlookers and photographers

Hundreds of photographers have swarmed to Yosemite national park to catch a rare glimpse of a "firefall" - a phenomenon that makes it appear as if water has turned into lava, flowing from a volcano.

For about 10 days each February, sunlight illuminates Horsetail Fall in a way that looks like lava is tumbling down the rock face. The light show can prove elusive - local photographers said this is the first February in four years in which conditions have been ideal to capture the firefall.