Archeologists have solved the mystery of the Thirteen Towers, a line of low stone structures that have spanned an arid Peruvian slope like a massive set of prehistoric teeth for 2,400 years.
The towers lined up outside the citadel at Chankillo are a massive solar observatory that marks not only the summer and winter solstices, but also the days and weeks of the year.
For The Record
Los Angeles Times Tuesday May 08, 2007 Home Edition Main News Part A Page 2 National Desk 1 inches; 47 words Type of Material: Correction
Peruvian observatory: A March 2 article in Section A about 13 stone structures that were part of an ancient solar observatory said Inca texts described similar "sun pillars" to mark seasonal events. The description should have been attributed to Spanish texts; the Incas left no written records.
The evidence that they are an observatory is unequivocal, said Clive Ruggles, a professor of archeo-astronomy at the University of Leicester and one of the authors of the paper in today's issue of the journal Science.
"It seems extraordinary that an ancient astronomical device as clear as this could have remained undiscovered for so long," he said.
The site is not the oldest solar observatory in the New World. That honor goes to a 4,200-year-old site just north of Lima, Peru's capital, that marks the solstices. Other ancient structures have been found that clearly have astronomical alignments.
"Unlike all the other sites, however, [Chankillo] contains alignments that cover the entire solar year," said coauthor Ivan Ghezzi, who was a graduate student at Yale University when he did the work but is now archeological director of the National Culture Institute in Lima.
In effect, it is the oldest "full-service observatory" in the Western Hemisphere.
The finding is important because of the insight it provides on the culture of the indigenous peoples, who were ancestors of the Inca, said archeologist Clark Erickson of the University of Pennsylvania, who was not involved in the research.
"The real goal of archeology is not to find stuff, but to find out what was going on in people's minds in the past," he said. "The most important thing is to people the past and make it come alive, and that is what this does."
Chankillo is a large ceremonial center covering a little more than 1.5 square miles of the Casma-Sechin River basin in the coastal Peruvian desert.
Its most notable feature is the citadel, a 900-foot-long structure built within three concentric, roughly circular walls, with gates and defensive parapets. The citadel's resemblance to the head of an electric shaver has led some observers to refer to it facetiously as "Norelco-land."
Archeologists have argued for more than a century over the citadel's purpose. Many believe it is a fortress, but the lack of water inside suggests that is unlikely. The new findings support the argument that it is a ceremonial center of some sort.
