Ancient Lunar Observatory Discovered in Peru's Casma Valley

A new astronomical observatory has been uncovered in Peru’s Casma Valley. The site appears to be far older than any previously known in the Western Hemisphere. Archaeologists believe it was used to track both the sun and the moon with remarkable precision. The discovery places the Casma Valley among the world’s most significant ancient astronomical hubs. The region already hosts the Chankillo Solar Observatory, a UNESCO World Heritage Site built around 250 B.C.E. That structure uses an artificial horizon to pinpoint solstices, equinoxes, and other key dates within a one- to two-day margin.

The newly found observatory includes a corridor aligned with the lunar cycle. Unlike Chankillo, which focuses on solar events, this site suggests a broader understanding of celestial movements. Inside, researchers uncovered a ceremonial vessel in the Patazca style, hinting that cultural elites may have overseen its construction or rituals. The exact age of the site remains unclear. Radiocarbon dating is still underway, but early estimates propose it could predate Chankillo by centuries. If confirmed, this would push back the timeline of advanced astronomical practices in the Americas.

The find deepens insights into how ancient societies studied the solar system. With both solar and lunar tracking capabilities, the observatory reveals a sophisticated grasp of astronomy. Its discovery also reinforces the Casma Valley’s status as a critical centre for early celestial observation.