At first glance, this just appears to be a city covered in fog, but it’s actually an optical illusion that nobody can explain. After heavy rainfall in China’s Huangshan area, above the Xin’an River, this mysterious mirage of what appears to be a city, complete with people, trees, and even buildings, magically appeared. Continue reading for a video and more information.

This sighting wasn’t the first, as locals have spotted similar optical illusions in the area recently, but this one was the most puzzling. On a clear day, you would see blue skies in place of the buildings, trees, and people, since Huangshan is a mountain range in southern Anhui province in eastern China.