In a new research, archaeologists have discovered about 300 strange geoglyphs in the Amazon rainforest.
The geoglyphs, which are large geometric designs carved into the ground, are believed to have been sculpted by ancient people from the Amazon region around 700 years ago, though their purpose is still unknown.
According to a report in Science and Technology, so far, nearly 300 geoglyphs have been identified.
But, with advances in satellite imaging and increased clearing of the jungle coverage, scientists are hoping to discover many more of these strange, geometric designs.
One of the factors that contributed to so many geoglyphs being undetected prior to the aid of satellites is their enormous size.
Leading geoglyph scientist Alceu Ranzi said that his latest discoveries - five sets of geometric shapes, with circles, squares and lines - can measure more than a mile from one extreme to another.
Because they have been so hard to find, the first geoglyphs weren't discovered until the 1970s.
Since then, scientists have been trying to piece together what significance they may have had to ancient Amazonians.
What ever the purpose may have been, there's one thing that is certain that the ancient civilizations of the rainforest were more numerous and sophisticated than previously imagined.
The new marks were only discovered because the jungle coverage had been removed to due to deforestation in the Amazon.
These structures are deep, with grooves are as large as 12 meters wide and four deep, but it is believed that they were built when jungle abounded, which would make their construction all the more difficult.