A tiger yawns next to a piglet at the Sriracha Tiger Zoo, in Chonburi province, Thailand, June 7, 2016. (Photo by Chaiwat Subprasom/Reuters)

People walk on a sightseeing platform in Zhangjiajie, Hunan Province, China, August 1, 2016. China has opened a 100-metre-long glass skywalk stretching around a cliff on the side of the Tianmen Mountain. The skywalk provides a view of a 300-metre drop and overlooks Tongtian Avenue, a mountain road with 99 turns that snakes up the mountain. When translated in English, it means “Avenue to the Sky”. (Photo by Reuters/Stringer)

In the mountains of central Vietnam, a colossal pair of hands lifts a golden thread of walkway high above the clifftops, as if the mountain itself has sprouted limbs. Here: A giant hand structure at the Gold Bridge is seen on Ba Na hill near Danang city, Vietnam on August 1, 2018. (Photo by Reuters/Kham)

Photo taken on January 3, 2018 shows the snow-light show at the Sun Island International Snow Sculpture Art Expo in Harbin, capital of northeast China's Heilongjiang Province. Snow Wonderland, a 3D snow-light show applying modern sound, light and digital technologies has been displayed at Sun Island International Snow Sculpture Art Expo recent days. (Photo by Wang Jianwei/Xinhua via Getty Images)

The Buddha Dordenma statue overlooks the town of Thimphu, Bhutan, April 16, 2016. (Photo by Cathal McNaughton/Reuters)

A nesting bird peeks out of the budding Japanese Yoshino cherry tree along the Tidal Basin in Washington, Sunday, April 7, 2013. Despite repeated predictions peak blossom time for the historic cherry trees is not yet here, but almost, almost. (Photo by Carolyn Kaster/AP Photo)

A church made entirely from ice is seen during the night at Balea Lac resort in the Fagaras mountains January 29, 2015. (Photo by Radu Sigheti/Reuters)

A motorcyclist dodges in the annual water-splashing festival to mark the New Year of the Dai minority in Menglian, Yunnan province April 13, 2015. (Photo by Wong Campion/Reuters)