Most people would steer clear of the notoriously dangerous slums of Rio de Janeiro, where drug gangs roam the deteriorating city streets. We imagine very few people would attempt to paint the run-down ghetto in rainbow bright hues. But that is exactly what artists Jeroen Koolhaas and Dre Urhahn, who go by Haas & Hahn, chose to do.

From 2007 to 2010, the Dutch duo embarked on an extreme urban makeover, turning some of the world's most dangerous slums into a real-life Candyland board. We stumbled upon The Telegraph's look back at Haas & Hahn's incredible project and decided to revisit their epic square-wide mural, which the New York Times called a "radiant, updated form of real-life Cubism."

Check out the Rio de Janeiro streets before...
street art slums

And after...
street art slums

Rio's slums, or favelas as they are known, aren't the only urban sites Haas & Hahn transformed into explosions of color. Beginning in 2011 the pair spent 18 months in Philadelphia's Germantown, where they embarked on Philly Painting, "a social and artistic experiment of urban acupuncture, beautification, and economic stimulus of unprecedented scale."

What do you think of Haas & Hahn's colorful makeover? Let us know your thoughts in the comments.

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  • Artists Haas & Hahn in Santa Marta.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

  • Artists Haas & Hahn painted the entire Santa Marta favela in Rio de Janeiro.

See a video of Philly Painting in action below:

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