Brain scans of modern listeners suggest that Aztec whistles sound like human screams, which may have prepared sacrifice victims for their journey to the underworld.

According to Phys, the macabre Aztec hoard now totals 603 human skulls. Mexico’s National Institute of Anthropology and History (INAH) discovered this facade of the tower months ago, but only ...

Others think they may be relics from the legendary island of Atlantis or proof that extraterrestrials visited the Aztec sometime before the Spanish conquest. Stories about the skulls focus heavily ...