an excellent candidate for high precision dating. The site may date even earlier, however, as samples from the oldest parts of the excavation have yet to be dated. Caral had a population of approximately 3,000 people. However, 19 other sites in the area (posted at Caral), allow for a possible total population of 20,000 people sharing the same culture in the Supe Valley. All of these sites share similarities with Caral, including small platforms or stone circles. Shady believes that Caral was the focus of this civilization. It is believed to be part of an even more vast cultural complex, trading with the coastal communities and the regions farther inland. She suggests that a depiction of monkeys may be evidence of trade with communities along the Amazon. Geoglyph In 2000, Marco Machacuay (the chief of excavations at the time) and his colleague, Rocío Aramburú, discovered a large shape etched on the ground among circular stone lines near Caral. This image, known as a geoglyph, is located on the desert floor just west of the main site at Caral. The lines form the design of a human face with long, streaming hair and a gaping mouth. This geoglyph is similar to bleeding figures with a similar gaping mouths found etched onto the stone walls at a site called Cerro Sechín, in the Casma Valley to the north. What this figure represents is unclear. It is believed to have been constructed around the same time as Caral and to have been associated with a nearby ceremonial site known as Chupacigarro. Musical instruments Another significant find at the site was a collection of musical instruments, including 37 cornetts made of deer and llama bones and 33 flutes of unusual construction. The flutes were radiocarbon dated to 2170±90 BC. City layout The city of Caral was split into two sections, an "Upper Half" and a "Lower Half". These halves were divided naturally by the Supe River Valley. In the Upper Half there are six monumental complexes, each of which includes a pyramid, open plaza, and assemblage of residential buildings. In the Lower Half there are residential buildings, small pyramids, and one monumental complex called the "Temple of the Amphitheater". The Upper Half complexes were all constructed around a pyramid. These are the "Great Temple/Great Pyramid", "Central Pyramid", "Quarry Pyramid", "Lesser Pyramid", "Pyramid of the Gallery", and "Pyramid of the Huanca". The associated residential structures