Ancient Astronomical Observatory in Peru

via ScienceDaily this time.

The earliest known astronomical observatory in the America discovered in Chankillo, Peru. The site has long been known but the mysterious 13 stone observatory nearby was only recently analyzed, both to determine its use and age. It dates back to the 4th century BC, 500 years before similiar finds built by the Mayans in Mexico.

"Chankillo is a large ceremonial center covering several square kilometers in the costal Peruvian desert. It was better known in the past for a heavily fortified hilltop structure with massive walls, restricted gates, and parapets. For many years, there has been a controversy as to whether this part of Chankillo was a fort or a ceremonial center. But the purpose of a 300meter long line of Thirteen Towers lying along a small hill nearby had remained a mystery..
The new evidence now identifies it as a solar observatory. When viewed from two specially constructed observing points, the thirteen towers are strikingly visible on the horizon, resembling large prehistoric teeth. Around the observing points are spaces where artifacts indicate that ritual gatherings were held. The current report offers strong evidence for an additional use of the site at Chankillo -- as a solar observatory. It is remarkable as the earliest known complete solar observatory in the Americas that defines all the major aspects of the solar year."

Inca rulers considered themselves descended from the Incan Sun god, and such a site would have had important cultural and political significance. The site was used to track the rising and setting of the sun to denote the timing of both religious festivals and planting and harvest cycles. The early dating of the site suggests that detailed astonomical data had been gathered even earlier, leading to the construction of the sites by ruling political and religious castes in order to cement their power over the population.