Tourists visit the Mogao Caves in Dunhuang, Northwest China’s Gansu province on May 1, 2019, the first day of the four-day May Day holiday. [Photo/Xinhua]

Tourists visit Beijing International Horticultural Exhibition in Beijing, capital of China on May 1, 2019, the first day of the four-day May Day holiday. [Photo/Xinhua]

Tourists visit an aquarium in Shenyang, Northeast China’s Liaoning province on May 1, 2019, the first day of the four-day May Day holiday. [Photo/Xinhua]

Tourists visit the Xixi national wetland park in Hangzhou, East China’s Zhejiang province, May 1, 2019. Tourism boosts as many people go out for recreational activities during China’s four-day Labor Day national holiday. [Photo/Xinhua]

Tourists visit the Senado Square in South China’s Macao, May 1, 2019. Tourism boosts as many people go out for recreational activities during China’s four-day Labor Day national holiday. [Photo/Xinhua]

Tourists take part in an aquatic activity in the Boundary Island scenic area in Lingshui Li autonomous county, South China’s Hainan province, May 1, 2019 Tourism boosts as many people go out for recreational activities during China’s four-day Labor Day national holiday. [Photo/Xinhua]

Tourists take sightseeing boats at the Donghu scenic area in Shaoxing, East China’s Zhejiang province, May 1, 2019. Tourism boosts as many people go out for recreational activities during China’s four-day Labor Day national holiday. [Photo/Xinhua]

Tourists join a puppet parade held at the Sinan Mansions in East China’s Shanghai, May 1, 2019. Tourism boosts as many people go out for recreational activities during China’s four-day Labor Day national holiday. [Photo/Xinhua]