When you look at this photo, what do you see?
The latest mind-bending optical illusion that is taking the Internet by storm is a photo of what appears to be a small piece of rock stuck in a crevice of a red brick wall.
The image was uploaded to Facebook on Monday, and has since gone viral, racking up nearly 50,000 shares and more than 63,000 comments on the social networking site.
"This is one of the best optical illusions Iv [sic] seen," posted user Arron Bevin on Facebook. "If you see it. Don't spoil it!!!!!"
"You can't not see it once you see it!!!" he commented, adding that it took about five minutes before he could figure out the puzzling image.
What do you see in the photo besides a plain old brick wall? Take another closer look.
Some Facebook users have pointed out that it is a brown cigar sticking out of the bricks. That's five minutes of your life you'll never get back.
Fox News noted that the brick wall optical illusion follows the infamous dress posted on Tumblr in 2015, sparking a debate throughout social media about whether the color of the dress was black and blue or white and gold.
One user even went as far as Photoshopping a shadow the picture to help others unable to figure out the mystery of the brick wall.
Others took to Twitter to boggle other people's minds.
"It's took me a full day to work this out.. It's not just a brick wall.. Can you see it #opticalillusion," model Sam Reece tweeted.
Some Twitter users went beyond five minutes trying to work out the illusion.
"This brick wall illusion made me go loco after staring at it for about half an hour," user Andy said.
Others just wanted to know the answer already.
i see people on my tl saying they know the answer to that brick wall illusion, spill it already
— haemi (@bIondesmiles) May 17, 2016