This undated photo shows a spectacular sea of clouds appear in the Yitulihe National Wetland Park in Inner Mongolia. The forest atmosphere and the sea of clouds turned the park into a fairyland. (Photo/Lyu Haojun)

This undated photo shows a spectacular sea of clouds appear in the Yitulihe National Wetland Park in Inner Mongolia. The forest atmosphere and the sea of clouds turned the park into a fairyland. (Photo/Lyu Haojun)

This undated photo shows a spectacular sea of clouds appear in the Yitulihe National Wetland Park in Inner Mongolia. The forest atmosphere and the sea of clouds turned the park into a fairyland. (Photo/Lyu Haojun)

This undated photo shows a spectacular sea of clouds appear in the Yitulihe National Wetland Park in Inner Mongolia. The forest atmosphere and the sea of clouds turned the park into a fairyland. (Photo/Lyu Haojun)

This undated photo shows a spectacular sea of clouds appear in the Yitulihe National Wetland Park in Inner Mongolia. The forest atmosphere and the sea of clouds turned the park into a fairyland. (Photo/Lyu Haojun)