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)

Nelson Hernandez flashes the victory sign as he shows off one of the voodoo dolls that he is selling at El Viejo Lazaro Botanica to try and help the Miami Heat fans root their team on against the Dallas Mavericks in the NBA finals on June 9, 2011 in Miami, Florida. The dolls made from cotton come in white or black and they are all the same size. The user of the doll must have the name of the player attached to the doll, which is filled with cotton, herbs, sticks and a special powder. (Photo by Joe Raedle/Getty Images)

“Happy Feet” the emperor penguin that washed up on the Kapiti Coast last week, undergoes a medical examination at Wellington Zoo on June 29, 2011 in Wellington, New Zealand. The young penguin landed on NZ shores last week, after traveling over 3,000 kilometres from the antarctic. The ill penguin was operated on at Wellington Zoo several times this week to remove sand and sticks from it's stomach with hopes it will recover fully. A team of experts is likely to decide today, whether the bird will remain in captivity in New Zealand, or be transported back the the antarctic. (Photo by Hagen Hopkins/Getty Images)

A hat and boots belonging to a volunteer with the Israeli Antique Authority are seen inside the Cave of the Skulls, an excavation site in the Judean Desert near the Dead Sea, Israel June 1, 2016. A team of volunteers and archaeologists are searching for remains of The Dead Sea Scrolls, one of the oldest known Hebrew texts, in a national bid, initiated by the Israel Antiquities Authority (IAA), to prevent the robbery of such important artefacts and once found to hand them over to the state for preservation. (Photo by Ronen Zvulun/Reuters)

Britain's Prince Harry meets Chewbacca during a visit to the Star Wars film set at Pinewood Studios near Iver Heath, west of London, Britain, April 19, 2016. Prince William and Prince Harry are touring Pinewood to visit the production workshops and meet the creative teams working behind the scenes on the Star Wars films. (Photo by Adrian Dennis/Reuters)