Thousands of tourists saw a mirage of very high clarity which lasted four hours off the shore of Penglai city in China.
The mist rose on the shore and created an image of a modern city with high rise buildings, wide city streets, fast moving cars, and crowds of people all over the place.
The detail was very visible.
Experts explained that a mirage is formed when moisture in the air becomes warmer than the temperature of sea water, which refracts rays of sunlight to create reflections of the landscape in the sky.

source: monstrous.com