People visit the artwork titled Seven Magic Mountains by artist Ugo Rondinone, Wednesday, May 11, 2016, near Jean, Nev. The artwork was recently completed in the desert south of Las Vegas. (Photo by John Locher/AP Photo)

A girl with her face painted to look like the popular Mexican figure called "Catrina", jumps as she takes part in the annual Catrina Fest in Mexico City November 1, 2015. (Photo by Carlos Jasso/Reuters)

A mahout rides on an elephant in the city of Amritsar, India, 08 November 2015. Such elephants are often accompanied by their caretakers who ask for alms from people in the streets. (Photo by Raminder Pal Singh/EPA)

A member of a local swimming club holds a Russian national flag as he dives in at the start of a 24-hour swimming marathon near the western Siberian city of Barnaul March 29, 2014. Thirty members of the club will swim in turn during the event, held to mark Crimea becoming part of Russia, local media reported. (Photo by Andrei Kasprishin/Reuters)

Cassandra Cantu shields her 7-week-old puppy Kamala from the snow as she walks with friends in the Bear Creek Dog Park in Colorado Springs, Colo., Sunday, May 11, 2014. A spring storm that has brought over a foot of snow to parts of Colorado, Wyoming and Nebraska and thunderstorms and tornadoes to the Midwest was slowing down travelers and left some without power Monday morning. (Photo by Mark Reis/AP Photo/The Gazette)

A colourful sky before sunrise on Whitley Bay beach on December 21, 2015, as December could be the mildest across a large part of England since records began more than 350 years ago, forecasters have said. (Photo by Owen Humphreys/PA Wire)

Completion is near on Monaco's tallest skyscraper ever, and its first new one since the 1980s. Fueled by a luxury-housing boom in the tax-haven nation, the Odeon Tower's so-called Sky Penthouse is expected to sell for more than any other apartment in the world has ever sold before. Photo: The five-story Sky Penthouse is expected to be complete in September 2015. The water slide extends from a dance floor in the residence down to a private infinity pool. (Photo by Tour Odeon)

An airplane passes the moon as it makes its approach to Philadelphia International Airport, Sunday, September 7, 2014, in Philadelphia. (Photo by Matt Rourke/AP Photo)