From BBCNews Science/Nature:
Towers point to ancient Sun cult
The oldest solar observatory in the Americas has been found, suggesting the existence of early, sophisticated Sun cults, scientists report.
It comprises of a group of 2,300-year-old structures, known as the Thirteen Towers, which are found in the Chankillo archaeological site, Peru.
The towers span the annual rising and setting arcs of the Sun, providing a solar calendar to mark special dates.
(snip)
The rectangular structures, between 75 and 125 square metres (807-1,345 sq ft) in size, and are regularly spaced – forming a “toothed” horizon with narrow gaps at regular intervals.
About 230m (750ft) to the east and west are what scientists believe to be two observation points. From these vantages, the 300m- (1,000ft-) long spread of the towers along the horizon corresponds very closely to the rising and setting positions of the Sun over the year.
This is an interesting find. It is the first found in the Americas, according to the article. There’s some good scene/plot fodder there.