Masked revellers pose during the Venice Carnival in Venice, Italy February 11, 2017. The Venice carnival in the historical lagoon city attracts people from around the world. (Photo by Tony Gentile/Reuters)

Visitors and tourists walk around the ancient monument at Stonehenge on March 2 2012 in Wiltshire, England. The English Heritage, managed prehistoric UNESCO World Heritage site, believed to have been constructed in 3000BC, has always been a “must see” attraction for visitors to the UK and it is hoped that it will remain so for visitors to the London 2012 Olympic Games this summer. (Photo by Matt Cardy/Getty Images)

Elena Chernyshova's vision of Norilsk, Russia, the northernmost city in the world, is a series of surprises by which she extracts otherworldly beauty from ugly realities. Here: 2013. A woman is visible through a narrow passageway between two buildings. Norilsk's urban spaces were designed to shorten distances around large developments and give residents maximum protection from arctic winds. (Photo by Elena Chernyshova)

Swiss pilot Bertrand Piccard prepares for a test flight of the solar-powered Solar Impulse 2 experimental aircraft in Payerne November 13, 2014. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. An attempt to fly around the world in stages using only solar energy will be made in 2015. (Photo by Ruben Sprich/Reuters)

Sarah Gibbons grades a new batch of Maple Syrup at Gibbons Family Farm in Frankville, Ontario, Canada, 31 March 2014. The annual maple syrup season marks the end of the often brutal central Canadian winters and heralds the beginning of spring. The maple tree, whose leaf dominates the Canada's flag, plays both a symbolic and practical role in the identity of Canadians who produce around 95 percent of the world's supply of maple syrup. (Photo by Stephen Morrison/EPA)

An artwork entitled “Are you still mad at me?” by John Isaacs is displayed at the Death: A Self-portrait exhibition at the Wellcome Collection on November 14, 2012 in London, England. The exhibition showcases 300 works from a unique collection by Richard Harris, a former antique print dealer from Chicago, devoted to the iconography of death. The display highlights art works, historical artifacts, anatomical illustrations and ephemera from around the world and opens on November 15, 2012 until February 24, 2013. (Photo by Peter Macdiarmid)

Miss USA, Olivia Culpo, appears on stage during the Miss Universe Pageant at Planet Hollywood in Las Vegas, Nevada on December 19, 2012. Olivia Culpo was crowned Miss Universe 2012, beating out beauties from around the world to claim the coveted title. The title of first runner-up title went to the contestant from the Philippines, Janine Tugonon. (Photo by Joe Klamar/AFP Photo)