Ancient Astrological Observatory Discovered in Amazonian Forest

Archaeologists discovered 127 granite monoliths up to three-meters-high in the middle of the Amazonian forest, in the state of Amapa, northern Brazil, near the border with French Guiana. The 127 blocks of granite are driven into the ground and regularly placed in circles in an open field on top of a hill. Scientists say it is an astrological observatory possibly even 2,000 years old.

"Only a society with a complex culture could have built such a monument," told Mariana Petry Cabral an archaeologist from the Amapa Institute of Scientific and Technological Research to the 'O Globo' newspaper.

Cabral said the site resembles a temple and she inferred from the position of the stones, marking the winter solstice (when the sun is at its lowest in the sky), that it probably had been used as an observatory. In December, the path of the sun allows rays to pass through a hole in one of the blocks. People might have used this event to coordinate agricultural activity or as part of religious rituals. The site pre-dates European colonization and may cast new light on the region's past.

Archaeologists said the find holds mysteries similar to Stonehenge, in Salisbury, England, another monument of huge stones, whose purpose is also unclear. Stonehenge however is considerably older.

The exact age of the monument has been difficult to determine, but based on ceramic fragments found nearby, archaeologists estimate it between 500 and 2,000 years old. Scientists say this might be the oldest such observatory in Brazil.

The discovery is in Calcoene, 390 kilometers from Macapa, the capital of Amapa state.