structural:expansion
Culiacán, officially Culiacán Rosales, is a city in northwestern Mexico, the capital and largest city of both Culiacán Municipality and the state of Sinaloa. The city was founded on 29 September 1531 by the Spanish conquerors Lázaro de Cebreros and Nuño Beltrán de Guzmán under the name "Villa de San Miguel", referring to its patron saint, Michael the Archangel. As of the 2020 INEGI census, Culiacán had an estimated population of 808,416, placing it as the 21st most populous city in Mexico, while its metropolitan area had a population of 1,003,530, being the 17th most populous metropolitan area in Mexico. The city is in a valley on the slopes of the Sierra Madre Occidental, at the confluence of the Tamazula and Humaya Rivers, where both join to form the Culiacán River 55 m above sea level.