A hundred colorful hot air balloons hovered over Zhangye Danxia Geopark in China's northwestern Gansu Province on Friday at the park's first hot air balloon festival. /VCG Photo

The UNESCO-listed geopark is known for its unique Danxia landscape featuring reddish sandstone caused by wind and water erosion. /VCG Photo

During the festival, visitors can take balloon rides for a grand view of the mesmerizing natural wonder. /VCG Photo