They say it was probably a mirage, if so its quite detailed for a mirage... Mysterious 'ghost city' appears over a lake in China due to a natural phenomenon The apparition appeared in the afternoon over the Hongze Lake in the province of Jiangsu in eastern China, according to local media. Ancient Chinese buildings with curved roofs, trees and a giant wind turbine were among the eerie images rising up through the mist that had descended over the lake. There is usually nothing but sky across the horizon. It is believed that the sight was a mirage - a form of illusion that is common in humid weather. The phenomenon is caused when moisture in the air becomes warmer than the temperature of water below. As the rays of sunlight cross from the colder air into the warmer air it is 'bent' or refracted - creating a reflection in the air. The patterns in the mirage are typically blurred and shimmering with a resemblance to human structures. They are similar to a reflection seen in water.