Two girlfriends walk along a street off The Main in Montreal, seemingly oblivious to the bold pattern of waves directly beside and above them. This large graffiti mural lends flow and direction that the girls are following, in unbelievably bright, rich purple, pink, red, orange and brick. You have to wonder what the window on the bottom right corner of the wall opens up onto to. . . (Saint Laurent Boulevard is often referred to as The Main. It serves as the city's physical division of east and west. The boulevard traditionally divides Montreal by language, ethnicity, and class. Saint Laurent Boulevard was for generations the symbolic dividing line for the city, with the predominantly English-speaking population to the west, French-speaking population to the east, and immigrant communities in between along the Main and Park Avenue. The Main runs through many of Montreal's ethnic communities, a first stop for immigrant communities for over 100 years — initially Jewish, Chinese and Italian, and later Portuguese, Greek, Arab, Haitian and others. The southern section of the boulevard in downtown Montreal and the Plateau is lined with trendy shops and restaurants, and is the site of many street-fairs and festivals. What were once run-down factories have been turned into expensive lofts.