A loose translation of the news story at O Globo greatly assisted by Google because my Portuguese is awful.

Archaeologists have discovered in a remote region of Amapá what seems to be the biggest astronomical observatory in pre-Columbian Brazil. The observatory is formed by 127 granite megaliths, some up to 3 metres tall, distributed at regular intervals in a clearing 16km from Calçoene and 390km from Macapá.

The archaeologists say that only a society with a complex culture could have built the monument. For them the finding challenges the notion that no such societies ever developed in Amazônia. (more…)