A not-so-hidden DC treasure lies along the Red Line's tracks: a 700-foot wall that seems to swirl with eye-popping color.

Visible from the Rhode Island Avenue metro station, it showcases a constantly changing medley of artwork from graffiti artists, muralists, and anyone else who wants to pick up a brush or can of spray paint.

There are images and tags on many other buildings near this part of the line, a rapidly changing industrial area that is known as a graffiti hot spot. But the artwork on this wall, located behind the Rhode Island Avenue Shopping Center, is different. It is legal.

And it stands in loud defiance of both the surrounding gray cityscape and stereotypes about graffiti. 

Apart from the mural closest to the metro, which was commissioned by the DC Commission on the Arts and Humanities, the Edgewood wall is part of artist collective Albus Cavus' "Open Walls" program. It provides free, lawful access to large-scale surfaces around the District for those who want to literally paint the town; the only rule is that the artists (who must check with Albus Cavus before going wild with spraypaint) must acknowledge that their work may be covered over at any time by other artists using the wall.

"Art shouldn't only be in museums, galleries and special places. It should be readily available to the public in public spaces," says Peter Krsko, Albus Cavus' executive director.

In a town where "free, public art" generally refers to the works hanging on the Smithsonian Institution's hallowed walls, the program makes a case for the value of art on the city's walls, too: as a tool to energize neighborhoods, foster communities, teach kids, and nurture creativity.

"It all started in New Jersey," Krsko says, specifically East Brunswick. With the help of local residents, Albus Cavus transformed a neglected path along the Raritan River into a vibrant "art walk." By cleaning up the area and letting artists treat the wall as their canvas, the previously forsaken trail became "like an outdoor gallery." It re-activated the space and became a popular place for people to walk, run, and bike, he says.

"Art shouldn't only be in museums, galleries and special places. It should be readily available to the public in public spaces."

After relocating to DC, Krsko began brokering agreements to use walls around the city in a similar fashion, embracing the idea that graffiti has the potential to revitalize streets and neighborhoods rather than deface them.

The sprawling Edgewood wall was the first to be transformed in 2009.

When Albus Cavus approached the property manager of the plaza, Len Harris, he immediately recognized the potential value in having artwork so prominently displayed.

"It's uplifting for the neighborhood and for the shopping center," Harris says.

And while some local stakeholders may have been initially skeptical of the project, the "community has embraced it," according to Harris.

He recently got a call asking if delivery trucks in the parking lot could be moved; they were blocking the mural.  

A number of other "open walls" followed soon after – located on an abandoned building, in the back of a community center, under an overpass, behind a juvenile detention center – in often drab or run-down areas.

As artists take their imaginations to the walls, the large, dramatic works have an invigorating effect on their surroundings.

"It beautifies the neighborhood. It brings a lot of color and life," says Corey Poole, the director of youth development at the Perry Center at 1st and New York Avenue NW. Since turning a wall at the back of the community services center's building into an open wall, "people have been more conscious of the space," he says. "People are paying attention to the artwork now; they aren't littering or loitering."

"It doesn't cost anything to residents or the taxpayers. It obviously visually improves the street, and in turn, there is less litter and more people taking care of the area. There is completely different energy" in places adjoining the open walls, Krsko says. They don't "look empty anymore."

"People are paying attention to the artwork now; they aren't littering or loitering."

It also gives residents the opportunity to take ownership of their neighborhood's transformation rather than "city planners saying, 'we are going to decide,'" Krsko adds.

At the Perry Center, many of the kids in the after-school program have painted on the walls as part of its arts programming, which Albus Cavus provides. "It definitely changes their perspective," Poole says, and shows them "that there can be beauty in their neighborhood."

The walls don't just provide a unique learning opportunity for kids, but also for artists who lack (legal) access to such large canvases. "You can try things out that you've never done before," says artist Alex Merritt, who has painted on several of the walls and credits the experience with giving him the confidence and experience he needed to go back to art school.

Moreover, because it is legal, artists don't have to work quickly and haphazardly.

"I had one lady come up and she made a point of saying that she liked that, since we were taking our time on it, because we had permission, it made it a lot nicer than stuff … that other people had done," Merritt says.

It is a sentiment that he often hears when painting on Albus Cavus' walls. Instead of "random stuff all over the place," neighbors enjoy the work of talented artists who can afford to take their time. And though each individual piece of artwork may be temporary, the effects of the wall are lasting.