Santiago de Cali, or Cali, is the capital of the Valle del Cauca department, and the most populous city in southwest Colombia, with an estimated 2,280,522 residents in 2023. The city spans 560.3 km2 (216.3 sq mi) with 120.9 km2 (46.7 sq mi) of urban area, making Cali the second-largest city in the country by area and the third most populous. Cali is the main urban and economic center in the south of the country, and has one of Colombia's fastest-growing economies. The city was founded on 25 July 1536 by the Spanish explorer Sebastián de Belalcázar.