A performance opens the World Horticultural Exposition in Nanhu Lake Park in Tangshan, North China Hebei province, on April 29, 2016. The expo opens to the public on May Day Holiday and will last 171 days to Oct 16. [Photo by Wu Yan/chinadaily.com.cn]

A woman performs at the launch ceremony of the World Horticultural Exposition in Nanhu Lake Park in Tangshan, Hebei province, on April 29, 2016. More than 50 countries and regions participate the expo. The number of visitors isexpected to reach 10 million. [Photo by Wu Yan/chinadaily.com.cn]

A bird's eye view of Nanhu Lake Park, the site of the expo, which is located in the center of Tangshan city and covers 22.6 square kilometers. [Photo by Wu Yan/chinadaily.com.cn]

Themed "City and Nature, Phoenix Nirvana", the expo includes six international and national flower competitions among other economic and trade, cultural and sports activities. [Photo by Wu Yan/chinadaily.com.cn]

A view of Lingnan Garden in the expo. There are dozens of national and international gardens, such as Hebei Garden, Imperial Garden, British Garden and Italian Garden, etc.[Photo by Wu Yan/chinadaily.com.cn]

Tangshan Planning Exhibition Hall among other exhibition centers and halls is also built in the expo. [Photo by Wu Yan/chinadaily.com.cn]