No that's not lava but it's what gets millions of people out to this attraction every year.

Blazing 'firefall' lights up Yosemite, see the pictures here

Thursday, February 16, 2017, 1:42 - It only happens once a year -- and only when a host of complicated factors are aligned -- but the show is always worth it.

Its mid-February, meaning Yosemite National Park's famous cascading golden "firefall" lights up the park's distinct El Capitan, drawing photographers from around the world.

The regularity of the amazing national phenomenon, and its reliance on the sun's angle, may put one in mind of Stonehenge, but the science behind the firefall -- actually El Capitan's Horsetail Falls -- is actually a little more complicated, and harder to pull off.

First, you'll need the sun to be at just the right angle to hit the waterfall, and that angle only occurs twice a year, in February and October. However, the falls' fiery appearance is only possible in February.

Every February a rare phenomenon makes Horsetail Fall @Yosemitenps glow like fire. Pic from Saturday by Ray Lee #California #firefall pic.twitter.com/Gxt2YlKav7

— US Dept of Interior (@Interior) February 14, 2017

That's because the falls are reliant on the weather: They're fed by runoff from the snow that falls on El Capitan over the winter, and then only if daytime highs are above zero, enough to cause some melt. In October, there's usually not enough snowpack to feed the falls.

Even when all those pieces fall into place, you'll only see the falls light up if there's no cloud cover, and even then for only ten minutes in a day.

It looks like this year was a good one for firefall watchers. Below is a selection of shots from photographers who made the journey.

One of my photos from Yosemite National Park's annual 'Firefall.' For more info, pics, and… https://t.co/4fnppXWt7x pic.twitter.com/b30lSb3Cqs

— Tom Bricker (@Tom_Bricker) February 15, 2017

I love these "Firefall" pics from @YosemiteNPS. #Yosemite #Nature #Beauty pic.twitter.com/cJLHU9v5Aw

— K. L. Connie Wang (@BeTheBuddha) February 15, 2017

“'Firefall' is illuminating Yosemite National Park ” 🔥🏔️https://t.co/wR20j9hUyQ pic.twitter.com/xKVNpofcD7

— M Sylvester (@Aria_Sylvester) February 15, 2017

Firefall, Yosemite National Park, California pic.twitter.com/aXDhSHH5ye

— Ruby Lalor (@RedRose2201) February 15, 2017

Sangeeta Dey Photography ~ The Return of Firefall https://t.co/fWDhNIRApY pic.twitter.com/l9YWmAn6ZR

— ricky st.john (@rickyst_john) February 15, 2017

Firefall, which only occurs in the middle of February if very specific conditions are met, was out in full force today. I'd never witnessed it before, and it was absolutely worth the three-hour drive out (and three hours back), just to see it. (This update is a crosspost from my ongoing 365 project. More photos are available on my tumblr at vagabondvivant.tumblr.com)

A post shared by mike ricca (@vagabondvivant) on Feb 15, 2017 at 12:20am PST

Firefall 2017- it's that time of year again for the famous #firefall #yosemitenps. This trip almost didn't happen due to the crazy road conditions at Yosemite. There has been so much water that a lot of the roads were closed due to mudslides. Somehow we made it here at the very last minute. I still think the mist I saw last year was better but it wasn't bad this time either. Please scroll down on my feed to see previous years firefall if you like. Had an awesome time with some fun and talented photographers @naminou @jc.liang @sinanuong. Was suppose to meet up with a couple more but got lost in the rush. For those that plan on going to see this, be careful since there has been so much water that some of the roads are falling apart. Had an awesome weekend!!! - A special thank you to my wife for letting me go on these crazy fun trips before I get too old to travel. - - #usaprimeshot #pixworld_ #igworldglobal #artsyheaven #heatercentral #ig_color #worldcaptures #ouramazingearth #earthofficial #beautifuldestinations #special_shots #Earthpix #wildernessculture #travelstoke #foxnews #abc7now #ktvu #gottolove_this #yesabc #westcoast_exposures #sunsetstream_westside #yosemitenation #globeshotz #Nationalparkgeek @nationalparkgeek #worldprime #yescnn @awesome.earth.pix #awesomeearthpix #yesweather

A post shared by Ray (@rayophotography13) on Feb 12, 2017 at 10:07pm PST

Some things in this world remind you of just how magical this existence can be...and the #FireFall phenomenon that happens at Horsetail falls in #Yosemite is definitely one of them. I'll post soon about the serendipitous manner than allowed me to be here for such a remarkable event. Ahh. A deep breath in...Hold...and...ouuuut. It's a great day to be an Earthling.

A post shared by Robert Kugler (@robkugler) on Feb 12, 2017 at 2:41pm PST

SOURCE: Yosemite Firefall

Follow Daniel Martins on Twitter