Women spray their designs on a wall during a graffiti class offered by the LATA 65 organization in Lisbon, Portugal May 14, 2015. The LATA 65 organization is an initiative for the elderly in the area of urban art. Since it began in 2012, they have introduced the world of graffiti to over 100 senior citizens, giving workshops in different neighborhoods of Lisbon. (Photo by Rafael Marchante/Reuters)

A woman looks at La Paz city from the Jacha Qhatu cable car station in El Alto, July 23, 2015. Bolivia already has the largest urban cable car system in the world. Now the booming country is tripling the size of the network and will soon have nine lines whizzing above the administrative capital of La Paz. (Photo by David Mercado/Reuters)

The series of shots show the bare steel infrastructure of the Bushfield army training camp near Winchester which was in operation during World War Two and was used to train Royal Green Jackets recruits in the sixties. The spectacular images were taken by an urban explorer who wished to remain anonymous. Here: A railway siding in Wiltshire, UK where ammunition was transferred by tunnel to an underground storage facility. (Photo by MediaDrumWorld.com)

Τhe hovering car without wheels, also called the hovercar, is a constant fixture in science fiction films, video games and comic books, and a long-standing dream for car lovers and technology fans alike. This dream is also shared by French photographer Renaud Marion, who creates images depicting hovering cars in everyday urban settings. In his ongoing photographic project titled ‘‘Air Drive’’, Marion combines retro car designs with futuristic technology, a project driven by his childhood visions of how the world was going to look like in the future. (Photo by Renaud Marion)

The Ring of Life is a 515-foot (approximately 157 meters) landmark built in the city of Fushun, China. The landmark is built with an observation deck accessible by elevator, as well as 12,000 LED lights. Having abandoned local entertainment projects due to the small local population, urban planners settled on building a sightseeing landmark instead in order to attract a tourist industry to the region. The structure uses approximately 3,000 tons of steel and cost an estimated $16M U.S. dollars.

A cat yawns at Nekorobi cat cafe on January 20, 2009 in Tokyo, Japan. Cat cafes, where people can spend time with their favorite cat for about 10 US dollars an hour, are now getting more popular with people living in urban areas. The regular customers are mainly in their 20's to 30's and seaking healing by cats, or people who cannot afford to have pets full time. Some visiters come to the cat cafe three times a week. (Photo by Junko Kimura/Getty Images)

Dancers take part in the Karneval der Kulturen (Carnival of Cultures) street parade of ethnic minorities, in Berlin, Germany, May 24, 2015. A few dozen dancers, musicians and performers from dozens of communities took part in the urban festival on Sunday that aspires to reflect the multi-ethnic diversity of the German capital. (Photo by Hannibal Hanschke/Reuters)

Stunning silhouettes under European cities reveal the size and splendor of the continent’s urban foundations. Photographer and content-manager Anna Arinova, 28, from Moscow, captured the awe-inspiring labyrinths in Russia and Germany. Here: Regenwurmlager, Poland. The Regenwurmlager is an extensive underground fortification area constructed by Germany in 1920s-1940s, now in western Poland, near the city of Międzyrzecz. (Photo by Anna Arinova/Caters News)