Culiacán is a city in northwestern Mexico, the largest city in the state of Sinaloa as well as its capital an capital of the municipality of Culiacán. With 605,304 inhabitants in the city (census of 2005), and 793,703 in the municipality, it is one of the largest cities in the country. The municipality includes such outlying communities as Costa Rica and El Dorado and has a total area of 4,758 km² (1,837 sq mi).