There are only about 51 days in a year on which tourists can catch a glimpse of the spectacle of sea of clouds in the Huangshan Mountains in east China's Anhui Province. 

The unique phenomenon is formed by the stratocumulus below the height of 2,500 meters and ground fog. In the mountain valley, lush vegetation and short exposure to sunlight make water vapor hard to evaporate, enabling bountiful vapor to accumulate.

Although you may see the sea of clouds throughout the year, it appears more often in the winter and spring, especially after the rain and snow. If there are more rainy days in a year, the sea of clouds is more likely to be seen.

(All photos via VCG.)

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