Advanced LiDAR surveys in the rugged Sierra Madre del Sur mountains have uncovered a hidden Zapotec citadel dedicated entirely to the extraction and refining of silver. The site, which dates to the Classic period, features a complex system of fortified terraces, smelting furnaces, and subterranean tunnels that suggest a highly organized industrial operation. Unlike the ritual centers of Monte Albán, this newly identified city appears to have been a purely economic and military outpost designed to control precious metal resources.
The mapping reveals an urban grid that includes barracks for laborers and several administrative buildings where silver ingots were likely assayed and stamped. This discovery explains the source of the high-quality silver jewelry found in elite tombs across the Zapotec region, which was previously a mystery. The isolation of the site and its defensive walls indicate that the Zapotec elite went to great lengths to protect their lucrative mining interests from rival Mesoamerican powers.