Illustration by H.M. Herget, National Geographic
An artist's conception shows Inca worshippers ascending the Temple of Pachacamac. In its Inca period, the Pacific-coast city remained a spiritual center—and even expanded.
Whereas the Ychsma domain likely included only local river valleys, pilgrims of the much more vast Inca Empire came to Pachacamac from as far away as 930 miles (1,500 kilometers), according to contemporary Spanish reports. "Huge facilities were built by the Incas for this big-scale pilgrimage," Eeckhout said.
The University of Illinois's Piscitelli added, "What's amazing about the site is that ... the [Ychsma] Pachacamac priests were still allowed to function independently of the Inca religious specialists and were even consulted by the Inca for advice."
Previously unearthed Ychsma skeletons suggest a high proportion of those buried at Pachacamac suffered from cancer, syphilis, and other serious conditions—backing up Inca-era testimony that the city was a "pre-Hispanic Lourdes," a font of supposed "miracle" cures, Eeckhout's team says.
Bones from the latest dig have yet to be analyzed for disease, but the simple grave trappings, which include copper and metal alloy items such bracelets, indicate that the dead were neither rich nor royal.
"We consider it a cemetery of the common people," Eeckhout said.
Photography by J. Enrique Molina, Alamy
Like most pre-Columbian cultures, the Ychsma left behind no written record, leaving archaeologists to puzzle out the culture's story from relics and ruins such as those at Pachacamac, shown above with a backdrop of modern development.
Other Ychsma sites—recognizable by their distinct architecture and artifacts—have been found nearby, Eeckhout said, but Pachacamac so far seems to have been their greatest settlement.
Despite his team's already 13-year excavation efforts, the Ychsma are still "one of the ancient cultures of Peru that remains to be explored," Eeckhout said.
The latest tomb finds, Piscitelli predicted, "will yield great insights into the religious and ceremonial activities that took place at Pachacamac."