Tourists walk on a wooden walkway to enter the Longmen Grottoes in Luoyang, central China's Henan province, in this file photo taken on April 21, 2012. According to the administration office of the Longmen Grottoes, 1.6 million tourists visited the grottoes in the first six months of 2012, rising by 30 percent on a yearly basis. The revenue of the same time period reached 125.74 million RMB yuan (19.72 million U.S. dollars), growing by 24 percent year on year. The Longmen Grottoes are one of the finest examples of Chinese Buddhist art.[Photo/Xinhua]