- British street art duo Nomad Clan have created murals all over the world
- "Athena Rising," in Leeds, is said to be the tallest in the UK
And while it's still associated with illegal graffiti, street art has increasingly become the subject of commissions from public bodies.
Nomad Clan are an internationally acclaimed street art duo from the UK, who have painted giant murals all over the world, commissioned by cities, galleries and non-profit organizations.
In 2017 they created what's been called the UK's tallest mural, in the city of Leeds. "Athena Rising" depicts a swooping owl -- an animal associated with wisdom and the ancient Greek goddess Athena.
It took them seven months to plan and a month to execute, painting for eight hours a day from a movable platform suspended from the building, and using just over 300 cans of spray paint.
The mural is more than 150 feet (46 meters) tall and 36 feet (11 meters) wide. That's taller than the Statue of Liberty, from head to toe.
But size isn't everything: from a poignant piece in London's St. Paul's cathedral, which highlighted the refugee crisis, to organizing workshops in a Calais refugee camp, Nomad Clan's work often tackles social, environmental and humanitarian issues.
"I think street art has always been about putting a message out there, questioning things and getting people thinking and talking," says Joy Gilleard, one half of Nomad Clan, who goes by the name Cbloxx.
"Just because we paint giant public art murals doesn't mean that we want to remove those elements from our work."
Find out more about Nomad Clan in the video above.