Tourists have fun at Xin'ao Aquarium in Qinhuangdao, north China's Hebei Province, May 2, 2019. Tourists logged 195 million domestic trips in China during the May Day holiday from Wednesday to Saturday, up 13.7 percent year on year. And tourism revenue increased by 16.1 percent to hit 117.7 billion yuan (about 17.5 billion U.S. dollars) in the past four days, according to estimates given by the Ministry of Culture and Tourism. Major online travel platforms have also observed trends in tourism upgrading. Travelers from 614 cities booked tours over the holiday to more than 90 countries through Ctrip, a Shanghai-based online travel agency. The agency said tourists born between the years of 1980 to 1999 were the dominant-age groups. Most traveled with their children. Airline bookings for children accounted for 10 percent of Ctrip's overall flight bookings. Bookings for first-class flights were also 30 percent more during this year's holiday compared to last year. (Xinhua/Cao Jianxiong)