“‘We have not only people from other parts of the state. We have people from other parts of the country who come here.’ Every year, drug tourists from all over the United States visit Kensington for the heroin.” In the NYT Magazine, Jennifer Percy visits the extreme edge of an all-too common case. A Philadelphia neighborhood is the largest open-air narcotics market for heroin on the East Coast. Addicts come from all over, and many never leave. Trapped by the Walmart of Heroin.