ZHANGYE -- Dozens of hot-air balloons glided over across the Colorful Danxia Scenic Spot in Zhangye City of northwest China's Gansu Province on Thursday to open the third Zhangye International Hot-air Balloon Festival.

Forty balloonists from around the country operated 40 hot-air balloons to take off from the scenic spot, hovering over the well-known Danxia landform, a landscape characterized by reddish sandstone features.
Six hot-air balloon flight shows will be performed by the 40 balloons during the festival. And a series of other activities such as the hot-air balloon-themed photography competition and short video contest will also be held as part of the festival.
Danxia landform refers to various geographical landscapes in parts of China. Millions of years ago, the area was part of the ocean. But eventually, the land lifted above sea level. Because of the shifts in sedimentary environments, layers have formed in different colors like red, purple, green and gray, presenting fascinating view.