“The larger of Valeriana's two monumental precincts has all the hallmarks of a classic Mayan political capital: enclosed plazas connected by a broad causeway; temple pyramids; a ball court; a reservoir formed by damming an arroyo (a seasonal watercourse); and a probable E-Group assemblage, an architectural arrangement that generally indicates a founding date prior to AD 150,” says the study, published in the journal Antiquity.