Tourists enjoy prairie scenery in Sunan Yugur autonomous county, Northwest China's Gansu province, July 29, 2015. Silk Road travel is increasingly popular among tourists from home and abroad. Gansu, a key corridor of the historic trading route, received 18.717 million person-time of tourists with the income of 11.3 billion yuan ($1.82 billion) during the recent Silk Road International Tourism Festival alone in 2015.