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)

Members of the Castellers “Vila de Gracia” start forming their famous human tower called “castell” in the Barcelona neighborhood of Gracia, Catalonia, Spain on Sunday May 19 2013. A “castell” is a human tower traditionally built during festivals in many places in Catalonia. At these festivals, several "colles" or teams compete to build the most impressive towers they can. (Photo by Emilio Morenatti/Associated Press)

Bride to be Lauren Cechak expresses her dislike for a wedding gown after trying it on during Filene's Basement's annual sale July 30, 2010 in Bethesda, Maryland. Hundreds of brides to be and their shopping teams line up early waiting to buy gowns at drastically low prices during the annual sale, dubbed the “Running of the Brides”. (Photo by Mark Wilson/Getty Images)

Katie Francis, a member of the Difficult Access Team from Wiss, Janney, Elstner Associates, inspects a gargoyle while rapelling down one of the north tower on the west front of the National Cathedral while looking for damage from August's magnitude 5.8 earthquake and high winds from Hurricane Irene October 17, 2011 in Washington, DC. DAT members used cameras, cell phones and iPad computers to record places on the cathedral's west front where damage was apparent. (Photo by Chip Somodevilla/Getty Images)

School children celebrate after being rewarded for their dance performance during India's Independence Day celebrations in Chandigarh, India, August 15, 2015. Indian Prime Minister Narendra Modi's independence day speech focused on measures his “Team India” had rolled out to include millions of poor Indians in the banking and insurance systems, policies for workers and farmers and successes in the fights against inflation and corruption. (Photo by Ajay Verma/Reuters)

A contestant of the World Beard And Mustache Championships poses for a picture during the opening ceremony of the Championships 2015 on October 3, 2015 in Leogang, Austria. Over 300 contestants in teams from across the globe have come to compete in sixteen different categories in three groups: mustache, partial beard and full beard. The event takes place every few years at different locations worldwide. (Photo by Jan Hetfleisch/Getty Images)