probablyasocialecologist:

The Maya city of Tikal is famous for its soaring palaces and temples. But something far more humble kept Tikal functioning: its water filtration system, the earliest known of its kind. Researchers recently discovered a volcanic mineral that captures microbes and heavy metals in one of Tikal’s largest reservoirs. Because the material is not found nearby, the finding suggests the presence of a deliberate filter.

The finding contradicts the long-standing idea that the ancient world’s technological prowess was concentrated in places such as Greece, Rome, Egypt, and China, says study co-author Kenneth Tankersley, an archaeological geologist at the University of Cincinnati (UC). “When it comes to purifying water, the Maya were millennia ahead.”

Nestled in the tropical forests of northern Guatemala, Tikal flourished for more than 1000 years. At the height of its prosperity, around 700 C.E., it’s thought to have been home to more than 45,000 people. “It was one of the preeminent Maya cities,” says Nicholas Dunning, a UC geoarchaeologist.