"I am always amazed by their beauty when I see them," said Icelandic iReporter Finnur Andresson, who submitted the photo to CNN. "It's like another world."
The Northern Lights, or aurora borealis, are often seen in the northernmost regions of the world, including Iceland, Canada, Greenland and Alaska. The natural phenomenon is caused when a solar wind -- electrically charged particles emitted by the sun -- interacts with Earth's magnetic field.
Congrats to CNN.com readers Russell Bowman and Thorunn Kristjansdottir for being the first to correctly answer Iceland in this week's photo challenge!
[Original post] Do you know where this photo was taken?
If you think you know the answer -- or if you just want to take a wild guess -- post it in the comments area below. Later in the day, we'll reveal where the photo was taken and give credit to those who figured it out first. (The more detail, the better!)
Each Monday morning, we'll post a new photo and challenge you to tell us its origin. The photo might be related to a prominent news story or theme -- or it might just be something that caught our eye.
CNN's Sarah Brown, Diana Holden and Susannah Palk contributed to this report.