Long ago, there were roaming llamas, lush green valleys, and a revered sun that rose in this place. When the Inca people arrived at the Casma River Valley, the stone observatory there once measured the passage of time with the sun, seeming like a miracle.
The Casma River Valley served as a fertile refuge in harsh climates. Snaking through the lush coastal region of Peru, it traversed arid deserts and rugged mountains like a thin green ribbon across vast grasslands.
Despite the Inca people in Peru having slaves cultivate the bountiful valley, the now-ruined solar observatory was not their creation. Located 250 miles north of Lima, there stands a dilapidated complex known as Chankillo, built by an even older civilization centuries before the Inca Empire’s rule.
Between 300 and 200 BC, the Casma culture constructed Chankillo near the coast of the Casma Valley. Despite its 2,300-year history, this solar observatory can still precisely track the sun’s path at different times of the year.
This impressive stone structure is believed to be an ancient calendar. Its functionality is tied to a row of 13 stout stone towers evenly distributed along the ridge like a giant ruler. From a specific distant vantage point facing east, observers at the observatory can witness sunrise between the towers.
By noting when the sun rises between specific towers or positions at either end, observers could determine the exact solar calendar date. The Casma culture did not follow today’s Roman calendar but a more ancient one, though both marked solstices.
The observatory also marked the summer and winter solstices. These days signify the longest and shortest days of the year, marking the beginning of summer and winter, respectively. Sunrise to the left of the observatory, the northern end, signaled the start of summer, while if the sun rose to the right, towards the southern end, winter was coming.
Sunrise at both ends of the observatory marked the summer and winter solstices, while any position between the 13 towers acted as a date within the two six-month periods. Its measurements could be accurate within a day or two, similar to how the ancient Casma culture read it. Today, this solar observatory is deemed unique and one of the oldest of its kind.
But Chankillo is not just the observatory. On a nearby mountain stands another impressive structure: a triple wall for strength, a false entrance to deter invaders, and a jumble of bricks in concentric rings believed to be remnants of a sturdy temple.
“Chankillo is a masterpiece of the ancient Peruvians. A masterpiece in architecture, technology, and astronomy,” Peruvian archaeologist Ivan Ghezzi told AFP while visiting the site. “It’s the cradle of American astronomy.”
In 2007, Ghezzi and his British colleague Clive Ruggles wrote a research paper on Chankillo suggesting that the towers served as a solar observatory marking solstices, aiding ancient peoples in tracking planting and harvest seasons and religious festivals.
For a long time, modern-day farmers in the Casma River Valley and along the fertile coastal regions (making Peru one of the world’s leading avocado producers) have sought to expand cultivation to lands housing these archaeological sites.
In 2020, amidst the COVID outbreak, archaeologists abandoned many sites in Peru. Farmers reportedly took advantage of this opportunity to plant crops within the boundaries of Chankillo.
Since the pandemic began, UNESCO has closed dozens of historical sites, including Chankillo and others worldwide.
In 2021, Chankillo, along with Thailand’s Kaeng Krachan forest and China’s ancient Quanzhou Port, was declared off-limits and designated as UNESCO World Heritage Sites to protect their remaining portions and deter farmers and looters.
In 2009, another ancient site in Peru, the continent’s oldest city of Caral with its six pyramids, became a World Heritage Site. Looking back decades ago, the renowned and towering Machu Picchu citadel in the Peruvian mountains has been safeguarded since 1983.
The original article entitled “Ancient Humans Built Observatory in Desert 2,300 Years Ago That Tells Exact Date Using Sun—But How?” was published on the English Epoch Times website.