roughly from 1800 BCE to 900 BCE. Textiles from this time found at Huaca Prieta are of astonishing complexity, including images such as crabs whose claws transform into snakes, and double-headed birds. Many of these images are similar to optical illusions, where which image dominates depends in part on which the viewer chooses to see. Other portable artwork from this time includes decorated mirrors, bone and shell jewelry, and unfired clay female effigies. Public architecture, including works estimated to require the movement of more than 100,000 tons of stone, are to be found at sites like Kotosh, El Paraíso, Peru, and La Galgada (archaeological site). Kotosh, a site in the Andean highlands, is especially noted as the site of the Temple of the Crossed Hands, in which there are two reliefs of crossed forearms, one pair male, one pair female. Also of note is one of South America's largest ceremonial sites, Sechín Alto. This site's crowning work is a twelve-story platform, with stones incised with military themes. The architecture and art of the highlands, in particular, laid down the groundwork for the rise of the Chavín culture. The Chavín culture dominated the central Andes during the First Horizon, beginning around 900 BCE, and is generally divided into two stages. The first, running until about 500 BCE, represented a significant cultural unification of the highland and coastal cultures of the time. Imagery in all manner of art (textiles, ceramics, jewelry, and architectural) included sometimes fantastic imagery such as jaguars, snakes, and human–animal composites, much of it seemingly inspired by the jungles to the east. The later stage of the Chavín culture is primarily represented by a significant architectural expansion of the Chavín de Huantar site around 500 BCE, accompanied by a set of stylistic changes. This expansion included, among other changes, over forty large stone heads, whose reconstructed positions represent a transformation from human to supernatural animal visages. Much of the other art at the complex from this time contains such supernatural imagery. The portable art associated with this time included sophisticated metalworking, including alloying of metals and soldering. Textiles found at sites like Karwa clearly depict Chavín cultural influences, and the Cupisnique style of pottery disseminated by the Chavín would set standards all across the region for later cultures. (The vessel pictured at the top of this article, while from the later Moche culture, is representative of the stirrup-spouted vessels