Sumatran tiger Jumilah is seen with one of her cubs on display at Taronga Zoo on October 25, 2011 in Sydney, Australia. The Sumatran tiger cubs, born in August to mother Jumilah, will meet the public for the first time this week. (Photo by Mark Kolbe/Getty Images)

Anti-government protesters react on the grounds of the Mezhyhirya residence of Ukraine's President Viktor Yanukovich in the village Novi Petrivtsi, outside Kiev February 22, 2014. (Photo by Konstantin Chernichkin/Reuters)

Law enforcement officers stand, with some turning their backs, as New York City Mayor Bill de Blasio speaks on a monitor outside the funeral for NYPD officer Wenjian Liu in the Brooklyn borough of New York January 4, 2015. Tens of thousands of law enforcement officers from across the country gathered on Sunday for the funeral of the second of two New York City policemen killed last month in an ambush that galvanized critics of Mayor de Blasio. (Photo by Shannon Stapleton/Reuters)

In this February 2, 2015 photo, tourists jump as they pose for a picture, after disembarking from the Ocean Nova cruise ship, on King George Island, Antarctica. This tourist season, which runs November through March, more than 37,000 visitors are expected to walk on the coldest continent on Earth, about 10 percent more than the year before. (Photo by Natacha Pisarenko/AP Photo)

The Wuppertal Suspension Railways is one a kind elevated railway located in Wuppertak, Germany. It is the oldest elevated railway in the world, though it doesn’t look like it. It is kept in great condition by the government and provides for a great attraction for the tourists. It provides a great overview, as it runs above a number of city streets and a small river. Moreover, since it is powered by electricity, it proves an ecologically clean method of travel for the residents of the city.

Tim Anderson final balanced rock stack in the Llano River. Tim Anderson, rock balancing “pro” from Pennsylvania, carefully worked to balance his stack on a dry spot in the Llano river Saturday March 12, 2016. He was an honored guest of the festival and enjoyed visiting Texas so he came for another year. The river was higher this year because of the rains so the balancers could not get to the better rock that were available last year. (Photo by Nell Carroll/American-Statesman)

A police officer pepper sprays a protester as another protester stands in front of the race director's car during a farmers' protest who attempted to block the stage' s route, during the 16 th stage of the 105 th edition of the Tour de France cycling race, between Carcassonne and Bagneres- de- Luchon, southwestern France, on July 24, 2018. The race was halted for several minutes on July 24 after tear gas was used as protesting farmers attempted to block the route. (Photo by Stephane Mahe/Reuters)

English fashion designer Mary Quant (R) with a group of models at Heathrow Airport, before leaving for a continental fashion tour, 18th March 1968. (Photo by Express/Getty Images)