Today we celebrate the birthday of Ansel Adams, an American photographer whose vision helped shape the world's perception of Yosemite National Park, which lies just across the border in California. Yosemite is renowned for its granite walls, dramatic waterfalls and striking light, all of which have inspired generations of artists. One of its most intriguing sights is the Firefall, a term that refers to two distinct events in the park's history. For decades, visitors gathered at Glacier Point to watch an artificial Firefall, in which embers were pushed off the cliff in a glowing stream of fire.

Far more mysterious is the natural Firefall at Horsetail Fall on El Capitan. On a few evenings in mid- to late February, the sunset hits the waterfall at just the right angle, turning it bright orange, as if molten lava were sliding down the mountain. Clear skies, sufficient water and perfect timing are all essential for this effect to occur. In 1973, Galen Rowell observed this rare phenomenon and took the first widely known photograph of the natural Firefall—bringing widespread attention to one of Yosemite's most remarkable sights.