"It is not the photos, but social media that makes the canyon something," Chang says.

It is also called Yucha Canyon by locals - yucha means "where the rainfall splits" in Chinese - was formed by the erosion of local Danxia sandstone, primarily due to flash flooding, over a period of 100 million years. The arid Loess Plateau used to be a rainy region covered by thick forests just 500 years ago, and the rainwater flowed into the basin above the slot canyon sections, picking up speed and sand as it ran through the narrow passageways created out of fissures left by earthquakes, experts say.