Huaca Prieta is the site of a prehistoric settlement beside the Pacific in the Chicama valley, Peru, occupied ca. 3100–1800 cal. BCE (approx. 2400-1600 14C yBP) before ceramics were introduced. It consisted of a huge mound of ash, stones, textiles, plants and shells, with some burials and constructions. It was first excavated by Junius B. Bird in 1946–1947 who excavated three large test pits in or beside it. The remains, now at the American Museum of Natural History in New York City, include many examples of complex textiles made with twining techniques which incorporated intricate designs of mythological humans, condors, snakes and crabs. The many stone artifacts were not fancy—fish net weights, flakes and simple pebble tools; there were no projectile points. In the upper part of the mound there were many underground structures of unknown function, some with burials. They were made of cobblestones cemented with an ash-water mixture. The inhabitants fished, gathered shellfish, and grew fruit, gourds, squash, peppers, beans, tubers and, importantly, cotton.
There is a low mound 70–170 m to the north (now called Monticulo Cupisnique) where Bird excavated three test pits. He found many ruins and much refuse, including ceramics of the Guañape, Early Cupisnique and Cupisnique cultures. The last is linked to the highland Chavín culture. A large tsunami damaged both mounds leaving a thick layer of cobblestones just north of the preceramic mound, at about 850 BCE, between the two Cupisnique phases. Maize was introduced to the region after the tsunami.
^Sigfried J. de Laet, Ahmad Hasan Dani, ed. (1996). History of Humanity: From the third millennium to the seventh century B.C. History of Humanity: Scientific and Cultural Development 2. UNESCO. p. 1100. ISBN92-3-102811-1.
^Clark, Grahame (1977). World prehistory in new perspective (3rd ed.). Cambridge University Press. pp. 432–433. ISBN0-521-29178-X.