VIDEO: 'Firefall' captured at Yosemite National Park

HOUSTON (WPVI) -- An optical illusion that looks like fire flowing off a cliff is a special treat seen only at this time of year at Yosemite National Park. And now you can see it by watching the video above.

Park rangers say it's the sun glowing through a waterfall. The angle of the sun has to be just right, which happens for a couple of weeks in February. The photo is courtesy of Sangeeta Dey Photography. Check out her stunning images on Instagram.

Photographers flock to the waterfall to capture its blazing splendor.