AdvertisementAncient Maya: Astronomers, Farmers ... And Salt Entrepreneurs?October 08, 2018Rachel D. CohenfacebookEmailAncient Maya ruins at Tikal in northern Guatemala, near the border with Belize. Researcher Heather McKillop explains that Maya sites like Tikal could have been popular marketplaces to trade salt and other commodities. (David DUCOIN/Gamma-Rapho/Getty Images)