Brazilian archaeologists say the extraordinary discovery of what appears to be a pre-colonial astrological observatory in the rainforest in the state of Amapa near the border with near French Guiana, throws new light on the ancient peoples of the Amazon, illuminating a far more intricate and advanced society than previously thought.
Indigenous Indians are thought to have built the observatory 2,000 years ago, placing 127 three-metre-high granite blocks in circles to mark cosmological movements.
"Only a society with a complex culture could have built such a monument," archaeologist Mariana Petry Cabral, of the Amapa Institute of Scientific and Technological Research (IEPA), told Aljazeera.net.
She said that the site resembles a temple and may have been used as an observatory.
Eduardo Goes Neves, an archaeologist at the University of Sao Paulo, says that there are no other similar structures like it anywhere in Brazil.
"I think it adds to the picture of more cultural and social diversity in pre-colonial Amazonia than was previously thought. Previous thinking considered pre-colonial Amazonian societies as fairly homogenous. The more we work in the area, the more diversity one finds," he says.
"We still don't know much of the archaeology of this area, despite more than 100 years of research. It's hard to tell what rituals they took part in. The idea of the place being a sort of observatory is a good one, but we still need to test it."
That's down to astro-archaeologists, who practise a branch of science which studies former astronomical knowledge as inferred from archaeological remains, which was first popularised when Gerald Hawkins proposed that Stonehenge was a kind of Neolithic computer.
Many of the world's indigenous peoples are thought to use symbolism of the sky on earth to harness the power of the celestial world. One famous example being the theory that the Pyramids of Egypt were an Earthy reflection of Orion's belt, a series of three stars in the constellation Orion.
In their groundbreaking book Heaven's Mirror, authors Graham Hancock and Santha Faiia (cr) attempted to prove that the mimicking of the sky on earth was endemic in the ancient world.
"A great pan-cultural theory of the meaning of life and mystery of death and the possibility of eternal life illuminated the ancient world. They left behind in all cases a distinctive package of myths, monuments and spiritual beliefs based upon complex astronomical cycles.
"These cycles are so minute and so obscure that they could have only have been detected by means of precise observations of the heavens consistently carried out over thousands of years," they wrote.
Neves says that the Amazonian alignments were first reported in the 1920s by German-Brazilian anthropologist Curt Nimuendaju. But it has taken until now for Cabral's team to prove the winter solstice theory.
The Stonehenge comparison with the Amazon discovery is due to the astronomical significance of both sites. When the sun rises in Stonehenge on summer solstice the first rays hit the centre of the monument. In the Amazon, the alignment is with the winter solstice.
Stonehenge, built in Wiltshire, England, pre-dates the Egyptian pyramids. The circle of standing stones were erected 4,500 years ago, but the earliest markings - holes for pine posts - have been found under the modern tourist car park estimated to be 10,000 years old.
The Amazon site is much younger and was discovered in Calcoene, just north of the Equator, in the state of Amapa. The site raises interesting questions of the origins of civilisations in the Amazon.
Neves says that there is general agreement that the Amazon observatory was the work of the ancestors of the Palikur indigenous peoples.
"This is based on the fact that these people and their ancestors have been living in the area for roughly 1,500 years, on comparison of contemporary and archaeological ceramics as well as the oral tradition. The structures may be more recent though, but my opinion is that they date from before the arrival of the Europeans," he says.
He says that for any hunter-gather group, like the Palikur, who lives with nature, a knowledge of the celestial bodies in inevitable.
Today there are estimated to be less than 1,000 Palikur in Brazil and another 500 in French Guyana.
Their mythical universe is created in three parallel layers, the deep world, the earth and the celestial. In the deep world, just below the surface of the earth, live the supernatural in human form. A "hole" allows travel between these two layers with the supernatural reappearing on earth 'dressed' as animals.
The celestial layer is made up of several layers of skies according to research by Curt Nimuendaju. Today, as a result of evangelism by missionaries, their religious world is a confusion between old and new beliefs. Jesus Christ, they say, lives on the highest level, while the vulture with two-heads lives on the second.
One of the great mysteries of Stonehenge is how the giant blocks of bluestones were transported by hand from 320 kilometres away in Wales. But it seems the Palikur didn't have to go to so much trouble.
One study claims that the blocks came from just one kilometre away. Another theory claims that the blocks could have been made on site with some method of liquefying and reforming, like concrete.
The discovery adds to another rather more modern Brazilian 'Stonehenge' - that of its very parliament.
The science-fiction-like city of Brasilia was created from scratch in the middle of thick jungle in the 1950s.
In designing the congress building, the architects aligned the two giant towers at the centre of the structure so that the sun rises directly between them on Republic Day, April 21.
To achieve such a feat with the parliament, the architects Oscar Niemeyer and Lucio Costa, had to plan the entire city around this alignment, which has the 8km axis of government buildings at its core.
But they couldn't have imagined that this futuristic Stonehenge could have had its' roots in their own country, on the edge of the Amazon.