The Nasca culture (also Nazca) was the archaeological culture that flourished from c. 100 BC to 800 AD beside the arid, southern coast of Peru in the river valleys of the Rio Grande de Nazca drainage and the Ica Valley. Having been heavily influenced by the preceding Paracas culture, which was known for extremely complex textiles, the Nasca produced an array of crafts and technologies such as ceramics, textiles, and geoglyphs, often of enormous scale, called the Nasca Lines. They built a large system of underground aqueducts that still function today. Nazca food chain was based on agriculture. The iconography on ceramics indicates a varied diet, composed of maize, squash, sweet potato, manioc and achira, and a small trace of various fish. The evidence of coca consumption can be seen through remains but also through ceramics. This is the same for the hallucinogenic San Pedro cactus, which has been illustrated in ceremonies on several polychrome pots and bowls. From 500 AD, the Nasca civilization started to decline and by 750 AD the civilization had fallen completely. This is thought to have occurred when an El Niño triggered widespread and destructive flooding destroying fertile lands. The Nazca culture is characterized by its beautiful polychrome pottery, painted with at least 15 distinct colors using a pre-fire painting that required a great deal of experimentation in order to know which slips produced certain colors. Archaeologists have excavated highly valued polychrome pottery among all classes of Nazca society, illustrating that it was not just the elite that had access to them. The Nazca had no writing system so the iconography or symbols on ceramics served as a means of communication. The motifs depicted on Nazca pottery fall into two major categories: sacred and profane. The Nazca believed in powerful nature spirits who were thought to control most aspects of life. The Nazca visualized these nature spirits in the form of mythical beings, creatures having a combination of human and animal/bird/fish characteristics, and painted them onto their pottery.