Geometrical earthworks found in the Amazon rainforest — dubbed the Geoglyphs of Acre — were once important ritual communication spaces, says a duo of researchers from the São Paulo University in Brazil and the University of Helsinki in Finland. Sa and Seu Chiquinho sites featuring circular, square, and U-shaped earthworks. Image credit: Sanna Saunaluoma. The Geoglyphs of Acre are more than 450 mysterious earthworks located in the Brazilian...
