Major Chinese tourist attractions have been packed with tourists since the four-day holiday started on Wednesday. /VCG Photo

Cities including Beijing, Shanghai, Hangzhou, Nanjing, and Changsha are experiencing a peak of tourist flow. /VCG Photo

On Thursday, the International Horticultural Exhibition, which kicked off on Monday in Beijing, welcomed over 120,000 visitors. /VCG Photo

Longmen Grottoes in central China's Henan Province, which represent the high point of Chinese stone carving, also attracted a large amount of tourists. /VCG Photo

China extended this year's Labor Day holiday from three days to four days. It has boosted people's interest for travel, said online travel agency Ctrip. /VCG Photo