These two young siblings appear to cling on to a tree for dear life and even hold hands as they learn the ropes of climbing, on June 25, 2013. (Photo by Tim Fitzharris/Minden/Solent)

“The Net thrower”. The fisherman are conducting activities on Situgunung Lake. Photo location: Situgunung lake, Sukabumi, West Java, Indonesia. (Photo and caption by Dody Kusuma/National Geographic Photo Contest)

A winter swimmer, wearing a Santa Claus hat to celebrate the upcoming Christmas, reacts as he plays on a frozen lake at a park in Shenyang, Liaoning province, December 22, 2014. The characters on the hat read: “Shenyang Winter Swimming”. (Photo by Reuters/Stringer)

Participants wearing costumes and masks take part in the first day of the traditional carnival parade in Mohacs, Hungary, 23 February 2017. The carnival parade of so-called busos, dressed in costumes with frightening wooden masks and using various noisy wooden rattlers, is traditionally held on the seventh weekend before Easter to drive away winter. (Photo by Sandor Ujvari/EPA)

An invalis asking alms walks past a girl posing for the picture in the center of Ukrainian capital of Kiev on August 17, 2016. (Photo by Sergei Supinsky/AFP Photo)

(L-R) Models Kylie Jenner and Kendall Jenner pose during the Universal, NBC, Focus Features, E! Entertainment Golden Globes After Party Sponsored by Chrysler held at the Beverly Hilton Hotel on January 8, 2017. (Photo by Christopher Polk/NBC/NBCU Photo Bank via Getty Images)

A man feeds monkeys at Longchi scenic area, in Dujiangyan, Sichuan province, China May 24, 2017. (Photo by Reuters/Stringer)

Fearless daredevils clamber up the worlds highest man-made climbing wall – running up the face of a 540ft dam. The Diga di Luzzone in Switzerland is considered by climbers as the Everest of wall climbing. (Photo by Ilana Marcus/Caters News)