Beginning in 1400 A.D., the societies inhabiting virtually all of the territory in the northern half of Chile, whether agricultural-pastoralist or nomadic hunter-gatherer, faced a dramatic change in their ways of life—their forced incorporation into Tawantinsuyu, the powerful Inca Empire that emerged from Cusco to expand across the continent and ultimately stretch from southern Colombia to central Chile. Imperial rule meant that economic activities that previously had been structured around self-sufficiency or small-scale exchange now were planned around the interests of the Inca State. The Incas’ greatest interest in this future Chilean territory appeared to be its mining resources, and they constructed many production centers to this end, including a smelter at Viña del Cerro in Copiapó and a gold panning site on the Marga Marga ravine, which flows into the ocean near the modern-day city of Viña del Mar. They also operated the San Bartolo copper mine, north of San Pedro de Atacama. To sustain this mining industry, groups of laborers were brought from around the region to perform different tasks. These workers had to be fed, of course, and so local agricultural production was intensified through large scale farming operations in places such as Socaire, in the Atacama salt flat.