A pair of young visitors rushes through a tunnel of colored lights at the annual Garden of Lights display at Brookside Gardens on December, 06, 2015 in Silver Spring, MD. (Photo by Bill O'Leary/The Washington Post)

People enjoy skating at the open air Christmas ice rink on the first floor of the Eiffel Tower after its reopening on December 19, 2016 in Paris The ice rink of about 200 square metres and on the first floor of the tower (57 metres above the ground) is open to the public until February 19, 2017. (Photo by Joel Saget/AFP Photo)

This picture taken on August 4, 2016 shows three orphaned orangutan babies hanging in a tree whilst attending “jungle school” at the International Animal Rescue centre outside the city of Ketapang in West Kalimantan. (Photo by Bay Ismoyo/AFP Photo)

Visitors to the Nightmare Fears Factory in Niagara Falls, Canada, are obliged to navigate their way round the supposedly haunted building in total darkness while live actors jump out of them. The Nightmare Fears Factory team have been using hidden cameras to take pictures of their guests' terrified reactions, which they've then posted on the company's Facebook page. And it turns out they're all pretty funny. (Photo by Nightmare Fears Factory)

Charlotte fights a monster with a “wand” in her bedroom in Laure Fauvel's “Terreurs”, 2014, in Paris, France. An imaginative photographer has brought to life monsters that haunt children's nightmares. Armed with sticks, wands and swords the eight and nine year-olds appear to be getting the upper-hand against the villains. Parisian photographer Laure Fauvel, 22, said: I wanted the children not be victims and to fight the monsters. (Photo by Laure Fauvel/Barcroft Media)

Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)