Two recent finds suggest that early South Americans may have been more attuned to the cosmos than commonly believed.

In Peru, archaeologist Robert Benfer, retired from the University of Missouri, and colleagues have unearthed a 4200-year-old temple in the Andean foothills that may be the oldest astronomical observatory yet found in the Western Hemisphere, built about the same time as Stonehenge.

Benfer found that certain features, such as this frowning face (above), aligned with other geographic features at precise angles. Consulting with a physicist, he learned that the angles are related to where the sun would rise or set during seasonal solstices and equinoxes. Benfer, who reported the discovery at a meeting of the Society for American Archaeology in Puerto Rico last month, says these features suggest that the temple was used to help plan crops. "It's the most sophisticated early public art that has been encountered up to now anywhere in the Central Andes," says archaeologist Richard Burger of Yale University.

Another recently announced find, in the Brazilian Amazon, has also drawn comparisons to Stonehenge. It consists of 127 evenly placed stones, each weighing several tons, driven into the ground in a pattern that might help pinpoint the date of the winter solstice. Archaeologists with the Amapa Institute of Scientific and Technological Research in Brazil say ceramics in the area date back 2000 years.

The Amazon contains few clues to past civilizations because people rarely built in stone, says archaeologist John Walker of the University of Central Florida. But researchers are "coming around to the notion that there were some large-scale and pretty sophisticated societies throughout the Amazon."

CREDIT: NEIL A. DUNCAN