A solar phenomenon found above mysterious pillars, or saywas, was likely designed to broadcast the ‘sacred power’ of the Inca

This article is more than 2 years old

This article is more than 2 years old

Growing up on the edge of the Atacama desert in northern Chile, Jimena Cruz was often made to feel ashamed of her indigenous identity.

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On visits to nearby petroglyphs, her father would explain their history, while her mother situated them in legend. “I always had this relationship between the scientific and the cultural,” said Cruz.

But at school, this kind of knowledge was mocked.

“One day they asked us what we wanted to be when we were big,” added Cruz. “I said that I wanted to be an archaeologist. But the teacher said that I should forget it, because Indians were only fit for giving birth.”

Twenty years later, Cruz is an anthropologist and curator at the Gustavo Paige archaeological museum – and she has played a key role in a project bringing together archaeologists, historians and astronomers to help solve a 500-year-old enigma.

Facebook Twitter Pinterest Jimena Cruz: ‘Being behind the saywa and seeing that the sun rose exactly above it ... it was incredible.’ Photograph: Westend61/Getty Images/Westend61

The investigation focussed on rows of cairn-like pillars – known in the indigenous Quechua language as the saywas, or markers – which are dotted throughout the desert, close to the ancient pathways of the Qhapaq Ñan – an Inca road network stretching from southern Colombia to central Chile.

Dr Cecilia Sanhueza, of Chile’s Pre-Columbian Art Museum, had studied the saywas for some 20 years.

But their true purpose was elusive. They were built in the middle of the desert, too sporadic to be milestones, and little use as signposts. “They had to have another function,” said Sanhueza.

A depiction of saywas from a 16th-century Quechua-Spanish dictionary. Photograph: scielo.cl

Sanhueza turned to the illustrated chronicles of Quechua nobleman Felipe Guaman Poma de Ayala and 16th-century Quechua-Spanish dictionaries, which suggested that many saywas had a calendrical, astronomical and religious purpose. On the winter and summer solstices, the sun god, Inti, was believed to “rest” atop them.

Sanhueza approached astronomers at the nearby Atacama Large Millimetre Array (ALMA) and European Southern Observatory (ESO), where astronomers Sergio Martin and Juan Cortés ran simulations of sunrises on selected dates – and found that the sun appeared to align perfectly with the markers.

“It was completely different to what we normally do,” said Martin. “But by collaborating we were able to understand the saywas more deeply.”

It seemed that – somewhat akin to Stonehenge – the saywas had a simultaneous calendrical, ritual and political purpose. The uncannily precise solar phenomenon above the Inca stonework was designed to broadcast the “sacred power” of the Inca, even 1,000 miles away from Cuzco, Sanhueza suggested. Others marked borders between different climactic zones.

Meanwhile, Cruz interviewed retired nomadic llama herders who had trudged the Qhapac Ñan a few decades ago. “I wanted to understand what the Inca would have experienced if they passed through here in winter,” said Cruz.

The team braved extreme heat, freezing cold and altitude sickness to properly survey the saywas for the first time in over 20 years.

Finally, on the autumn equinox in 2017, they waited for sunrise at a site called Vaquillas. Cruz performed a small ceremony with coca leaves. As if on cue, the sun rose directly atop the line of the saywas. “It was a very emotional and beautiful moment,” said Sanhueza. Three months later, on the winter solstice, they observed the same phenomenon at a separate site.

But the alignment of a third location remained a mystery. Cruz, recalling childhood family rituals observed in honour of Pachamama, the Andean earth mother, on 1 August, suggested observing them on that date.

The suggestion paid off. “Being behind the saywa and seeing that the sun rose exactly above it … it was incredible,” said Cruz.

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Cruz is recruiting local volunteers to help preserve them.

The findings – announced in April this year – are a personal vindication. But they are also likely to fuel growing interest in the distinct indigenous heritage of northern Chile.

“We’re from an Andean culture that has its own vision,” agreed Esteban Velásquez, former mayor of the nearby city of Calama and a congressman for a new regionalist movement. “Today, we’re writing and recovering our own history.”