SAO PAULO, Brazil - A grouping of granite blocks along a grassy Amazonhilltop may be the vestiges of a centuries-old astronomical observatory — a find that archaeologists say shows early rainforest inhabitants were more sophisticated than previously believed. The 127 blocks, some as high as 9 feet (2.75 meters) tall, are spaced at regular intervals around the hill, like a crown 100 feet (30 meters) in diameter.
On the shortest day of the year — Dec. 21 — the shadow of one of the blocks disappears when the sun is directly above it.
"It is this block's alignment with the winter solstice that leads us to believe the site was once an astronomical observatory," said Mariana Petry Cabral, an archaeologist at the Amapa State Scientific and Technical Research Institute. "We may be also looking at the remnants of a sophisticated culture."
The interesting thing about this stonehenge is its nearby proximity to the Marajoara culture on Marajó Island. A culture that built mounds and made pottery with complex artistic designs where cross symbols were abundant..