The Air2 (Air Squared) floating Bluetooth speaker from Axxess CE is displayed at CES Unveiled, the opening event for the media preview days at the 2015 Consumer Electronics Show, January 4, 2015 in Las Vegas, Nevada. The speaker which levitates over its own base is one of the winners for the CES Innovation Awards and is patent pending. (Photo by Robyn Beck/AFP Photo)

Members of the public interact with “Impulse” by Lateral O ce and CS Design during Lumiere London festival of light 2018 on January 18, 2018 in London, England. Lumiere London is a four night long light festival spanning the British capital with more than 50 artworks by UK and international aritsts. (Photo by Dan Kitwood/Getty Images)

A woman performs during a march to commemorate International Day for the Elimination of Violence Against Women, in Bogota, November 25, 2015. (Photo by John Vizcaino/Reuters)

Animal rights activists dressed up as rabbit carry signs that read “Ajinomoto Stop Animal Testing” as they protest outside Ajinomoto headquarters in Kuala Lumpur on January 20, 2023, ahead of Lunar New Year. Activists call for the end of Japanese food company testing on rabbits, dogs, pigs and other animals. (Photo by Arif Kartono/AFP Photo)

A member of Wagner group stands guard in a street in the city of Rostov-on-Don, on June 24, 2023. President Vladimir Putin on June 24, 2023 said an armed mutiny by Wagner mercenaries was a “stab in the back” and that the group's chief Yevgeny Prigozhin had betrayed Russia, as he vowed to punish the dissidents. Prigozhin said his fighters control key military sites in the southern city of Rostov-on-Don. (Photo by AFP Photo/Stringer)

Turkish artist Nezaket Ekici performs a live art performance entitled 'Emotion in Motion' on the first day of Art Basel 2015, Hong Kong, China, 13 March 2015. The Hong Kong show of Art Basel features 233 galleries from 37 countries and territories, presenting works ranging from the Modern period of the early 20th century to the most contemporary artists of today, according to the official press release. (Photo by Alex Hofford/EPA)

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.

Metropolitan Transit Authority (MTA) Police Officer Keith Flood trains with his K-9 partner Doc, a German Shepherd, inside the “warehouse room” at the new MTA Police Department Canine Training Center in Stormville, New York, U.S., June 6, 2016. (Photo by Mike Segar/Reuters)