MazatlÃ n is a city in the Mexican state of Sinaloa ; the surrounding municipio ( municipality ) for which the city serves as the municipal capital is also called MazatlÃ n. It is located at on the Pacific coast , just across from the southernmost tip of the Baja California peninsula . MazatlÃ n is a city in the Mexican state of Sinaloa ; the surrounding municipio ( municipality ) for which the city serves as the municipal seat is MazatlÃ n Municipality . It is located at on the Pacific coast , across from the southernmost tip of the Baja California peninsula .