Mexico is a country in North America, bordered in the north by the United States.
In the episode "Probably", Kenny arrives in Ensenada, Mexico after a bus drags him over the border. Eric Cartman is later sent to the same town when his church is shut down and Jesus Christ reasoned that it was a fate worse than Hell.
Mexico is the main subject of the episode "The Last of the Meheecans", during which Butters Stotch, as Mantequilla, inspires the Mexicans to immigrate back to Mexico from the US. The Mexican President, Felipe Calderón, reappears in this episode with a talking role.