Archaeologists have been aware of ancient sites in the area since at least the 1940s; early work occurred at Aspero on the coast, a site identified as early as 1905, and later at Caral further inland. In the late 1990s, Peruvian archaeologists, led by Ruth Shady, provided the first extensive documentation of the civilization with work at Caral. A 2001 paper in "Science", providing a survey of the Caral research, and a 2004 article in "Nature", describing fieldwork and radiocarbon dating across a wider area, revealed Norte Chico's full significance and led to widespread interest.