Iranian artist and designer Mehdi Ghadyanloo, with the help of the municipality, is slowly brightening up the city of Tehran one wall at a time. The 33-year old street artist has been painting murals and walls in Tehran for the last 5 years age, during which he’s reported to have painted over one hundred walls.

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

A woman walks past a caricature of Britain's Foreign Secretary Boris Johnson in east London, Britain November 18, 2016. (Photo by Andrew Winning/Reuters)

Artist Julien “Seth” Malland aka Seth Globepainter has become known around the world for his vibrant murals of people, most frequently children, who appear to be sucked into colorful rainbow-like voids. The figures are usually facing away from the viewer, their attention completely swallowed by pools of dripping color revealed behind drab, urban facades.

A girl walks in front of a graffiti painted on the wall of a house located inside the 15th-century complex built by Mameluk Sultan al-Ashraf Qaitbey, in Cairo's City of the Dead, Egypt February 13, 2017. (Photo by Amr Abdallah Dalsh/Reuters)

A mural signed by “TV Boy” and depicting Pope Francis and U.S. President Donald Trump kissing, is seen on a wall in downtown Rome, Italy on May 11, 2017. (Photo by Tony Gentile/Reuters)

Marcelo Gutierrez of Colombia in action during the Valparaiso mountain bike downhill race in Valparaiso, Chile on February 11, 2018. Runners from around the world participated in the mountain bike race on the streets of the port. (Photo by Rodrigo Garrido/Reuters)