A visitor walks past the life-size sculpture “Security Guard” by Marc Sijan at The Armory Show, New York's annual international art fair, at Piers 92 and 94 on March 9, 2012 in New York City. The show features paintings, photographs, sculpture and other works of art by artists including Andy Warhol, Cindy Sherman and Pablo Picasso. (Photo by Mario Tama/Getty Images)

Comandos de Salvamento rescuers Maria Martinez (L) and Ana Chichilla attend to a wounded homeless man in San Salvador, El Salvador July 16, 2016. The man was attacked with a machete by suspected gang members. In 2015, El Salvador registered a record 103 homicides per 100,000 habitants, making it one of the most dangerous countries in the world outside a war zone. But for many young people who have few chances to distance themselves from rivalries between so-called maras in their schools and neighbourhoods, a civil-society organisation called the Comandos de Salvamento, or Rescue Corps, has been a refuge. (Photo by Jose Cabezas/Reuters)

A girl wearing a mask takes part in a procession celebrating the religious holiday of Mawlid al-Nabi, the birthday of Prophet Mohammad, in Benghazi, Libya December 10, 2016. (Photo by Esam Omran Al-Fetori/Reuters)

A small section of the expanding remains of the Veil Nebula, a massive star that exploded about 8,000 years ago. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. Image taken by NASA's Hubble Space Telescope. Released September 24, 2015. (Photo by Reuters/NASA/ESA/Hubble Heritage Team)

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.

Members of the New Orleans Baby Doll Ladies march during the Krewe of Zulu parade at Mardi Gras in New Orleans, Louisiana U.S., February 28, 2017. (Photo by Shannon Stapleton/Reuters)

Female labourers wearing helmets take a break from laying underground electricity cables in Ahmedabad, India, March 7, 2016. (Photo by Amit Dave/Reuters)