Lost Observatory Unearthed in Peru May Be Older Than Chankillo — A Dual Solar and Lunar Complex

Archaeologists working in Peru’s Casma Valley have uncovered an astronomical installation that may predate the famed Chankillo Solar Observatory — long considered the oldest observatory in the Americas. Though radiocarbon dating is still pending, multiple lines of evidence indicate the newly identified installation could be centuries older than Chankillo.

New Evidence at a Famous Site

The discovery sits within the broader Chankillo Archaeoastronomical Complex on Peru’s north-central coast. The Peruvian Ministry of Culture reported that the structure’s solar orientation, stratigraphic context, and construction materials support its interpretation as an astronomical installation that likely predates the Chankillo Solar Observatory, which is generally dated to about 250 B.C.E. and is protected as a UNESCO World Heritage Site.

Solar And Lunar Observations

Unlike Chankillo’s principally solar design, the newly identified installation includes a corridor deliberately aligned to the lunar cycle. That alignment suggests the site was used for systematic lunar observations in addition to solar tracking. Because lunar observation requires more complex timing and horizon calculations than solar tracking, the find points to a sophisticated level of astronomical knowledge in the ancient Casma Valley.

Ritual And Political Connections

Excavators also recovered a large Patazca-style ceremonial vessel—about three feet tall and decorated with modeled clay figures of warriors in combat poses. The vessel’s iconography implies elite or political participation in activities at the complex and reinforces interpretations that the hilltop Fortified Temple and neighboring installations combined astronomical, ritual, and political functions.

“The existence of both observatories solidify Casma’s position as one of the world’s most important ancient astronomical centers,” the Peruvian Ministry of Culture said in a translated statement.

What Comes Next

Researchers emphasize that radiocarbon dating and further analysis are required to establish precise calendar dates. If confirmed, the new installation would expand our understanding of pre-Columbian astronomy in the Americas and underline how advanced astronomical practices were in the ancient Andes.