Women perform square dancing at a park square in Beijing, China, April 9, 2015. Chinese-style square dancing is running circles around other hobbies for the elderly, with millions taking to parks and plazas across China, swivelling their hips and rolling their arms – but it's not to everyone's liking. (Photo by Kim Kyung-Hoon/Reuters)

In this April 1, 2002, file photo, Mike Cole, of Jenkintown, Pa., right, performs a kick-flip over a trash can with his skateboard as tourists pose for photos in front of artist Robert Indiana's sculpture in John F. Kennedy Plaza, also known as Love Park, in Philadelphia. Granite slabs from Philadelphia's famed Love Park, a skateboarding mecca though for a long stretch an illegal one, are being shipped in 2017 to the city of Malmo, Sweden, nearly 4,000 miles away, for use in construction of a skate park there. (Photo by Douglas Bovitt/AP Photo)

A girl uses her mobile phone during the evening at the National Park in Khartoum, Sudan, April 24, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

The National parks department hosts the 30th annual “All-Women Lifeguard Tournament” in Sandy Hook NJ. July 30, 2014. (Photo by Anthony Causi)

A woman dives and pretends to ride a bike in Underwater Park in Pula, Croatia, August 1, 2017. (Photo by Antonio Bronic/Reuters)

A man performs a split as he practices Kung Fu at Beihai Park in Beijing, China August 20, 2017. (Photo by Reuters/China Stringer Network)

People dance in a park on a foggy day in Huai'an, Jiangsu province, China October 10, 2017. (Photo by Reuters/China Stringer Network)

Aerial view of pond cypress at Qinglongwan Forest Park near Ningguo, China on November 26, 2017. (Photo by Imaginechina/Rex Features/Shutterstock)