San Francisco de Quito, most often called Quito, is the capital city of Ecuador in northwestern South America. It is located in north-central Ecuador in the Guayllabamba river basin, on the eastern slopes of Pichincha, an active stratovolcano in the Andes mountains. With a population of 1,397,698 according to the last census (2001), and, as estimated by the municipality, approximately 1,504,991 in 2005, Quito is the second most populous city in Ecuador, after Guayaquil.