Colonia Guerrero is a colonia of Mexico City located just north-northwest of the historic center. Its borders are formed by Ricardo Flores Magón to the north, Eje Central Lazaro Cardenas and Paseo de la Reforma to the east, Eje1 Poniente Guerrero to the west and Avenida Hidalgo to the south. The colonia has a long history, beginning as an indigenous neighborhood in the colonial period called Cuepopan. The origins of the modern colonia begin in the first half of the 19th century, but most of its development occurred as a residential area in the late 19th and early 20th. Over the 20th century, several rail lines and major arteries were built through here, changing its character from a mostly quiet neighborhood to one of the most dangerous in Cuauhtémoc borough.