A mass pillow fight in Trafalgar Square in central London on April 5, 2014 on International Pillow Fight Day. (Photo by Jane Scanlan)

Tattoo artists work on clients during the second International Tattoo Festival in Sochi, Russia, April 23, 2016. (Photo by Kazbek Basayev/Reuters)

Granada’s International Poetry Festival is an extraordinary celebration of poetry that takes place across the entire city. For a week, every February, Granada is transformed into a virtual Capital of the World’s Poetry. Photo: A girl takes part in the “Burial of arrogance and haughtiness” carnival during the IX Poetry Festival in Granada, 45 km from Managua, Nicaragua on February 20, 2013. In this occasion the festival is dedicated to Nicaraguan poet Ernesto Cardenal. (Photo by Hector Retamal/AFP Photo)

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)

U.S. soldiers from 145th Field Artillery Battalion deployed from the United States fire Paladin self propelled gun during the Foal Eagle training exercise at firing point 180 at the Rodriguez Live Fire Range on March 15, 2012 in Pocheon, South Korea. (Photo by Chung Sung-Jun/Getty Images)

A tattoo of a weapon covers the arm of a female inmate waiting to compete in the annual beauty contest at Talavera Bruce penitentiary in Rio de Janeiro, Brazil, early Thursday, November 23, 2017. Jail authorities say they organize the annual contest to encourage self-esteem, fight idleness and promote integration among women prisoners. (Photo by Silvia Izquierdo/AP Photo)

Runners gather at the start line for the annual “Santa Speedo Run”, a charity race through the streets of the Back Bay neighborhood of Boston. (Photo by Gretchen Ertl/Reuters)

Hollowed pumpkins float on a lake Ludwigsburg Castle on September 19, 2010 in Ludwigsburg, Germany. (Photo by Ralph Orlowski/Getty Images)