Valparaiso graffiti tour: Chile's bohemian town of street art

Eddie Ramirez has just shattered all my preconceptions about street artists. He didn't arrive on a skateboard. He doesn't appear to have any tattoos or piercings and his sky-blue shirt is clean and neatly ironed.

Despite not conforming to my ill-informed stereotype, the enthusiastic 28-year-old has been part of the street art community in Valparaiso, the port city 120 kilometres north-west from Santiago, for the past three years. As well as creating his own street art, he helps visitors understand more about Valparaiso's art scene by leading walking tours.

What started as a form of protest against Augusto Pinochet's oppressive dictatorship during the 1970s has since blossomed into one of the world's finest collections of street art. Valparaiso has become a magnet for artists and now there's barely an unadorned wall, alleyway or staircase left in the city.

After meeting in Plaza Anibal Pinto, we stroll up one of the city's many "cerros" or hills. Along the way, Ramirez explains the difference between graffiti and street art, showing us examples of the simplistic initials or "tags" of the former and the more complex, colourful murals of the latter. Unlike tagging, the murals have all been painted with the permission of the building owner and many are genuinely spectacular, soaring several storeys high.

He also provides some insight into street art's rules and etiquette. Artists often work in crews (he's part of the Mambo For Life, or MFL gang) or in a master/apprentice relationship with a more experienced artist. Occasionally, there are rivalries between crews but most of the time people are respectful and won't knowingly paint over an existing artwork.

Unsurprisingly, Instagram is the preferred method of communication and Ramirez often uses the social media platform to connect and collaborate with other artists.

As we zigzag through the city's vertiginous streets, he points out the wide variety of styles – everything from stencil-based images of Jimi Hendrix to colourful cut glass tiled mosaics to monochrome cityscapes created using black marker pen. Some of the works are hyper-realistic – an image of a semi-naked sleeping woman looks like a photo from afar – while others are more symbolic, such as a vibrant depiction of a Peruvian Indigenous girl surrounded by parrots in the courtyard of a church.