Most people who have been outside on a hot day are used to seeing small mirages of puddles appear on the road, but few of us can admit to witnessing a mirage the size of a city.
But that's what happened for the people of Huanshan, China earlier this month when they looked over the Xin'an River to see tall buildings appear to rise out of the mist as it settled over the river at dusk. Residents are used to only seeing only sky across the horizon over the river.
"It's really amazing, it looks like a scene in a movie, in a fairyland," one witness told ITN News.
Residents speculated that the image may be a vortex to a lost civilization, but scientists are suggesting that it is a mirage.
A mirage is a naturally occurring phenomenon that happens because light travels on the fastest possible route instead of going in a straight line. The rays bend around denser, colder sections of air to show the image of a distant object.
In the case of road puddles, the light bends in the dips of the road because the air is less dense at lower levels. When it bends, it displaces the image of the sky above.
Light bends while traveling along the river because of the temperature difference between the water and air.