A 1,200-year-old ritual site located in Cotahuasi Valley, Peru, now known as Tenahaha, has revealed several tombs crammed with a maximum of 40 mummies each. At present, archaeologists have successfully acquired at 171 mummified corpses from seven tombs.

Justin Jennings, archaeologist and curator at the Royal Ontario Museum in Toronto, wrote in a section of the recently printed book Tenahaha and the Wari State: A View of the Middle Horizon from the Cotahuasi Valley that the dead, whose numbers were most likely by the thousands, rose over the living: the dead were placed in tombs located on small hills close to the Tenahaha site.

The researchers discovered that before the limbs of the corpse stiffened after dying, the mummified bodies had their arms collapsed along their frail chest and their knees placed up to their shoulders. The mummies were then tied with ropes and clothed in thick layers of fabric. The mummies range from fetuses to the elderly; a few younger mummies like babies were placed in jars. Based on the findings, the living resided in villages near Tenahaha.

Most remains were fragile and in poor condition, mainly due to water damage or even damage caused by rodents. Some parts of the corpses were intentionally separated.

Researchers also found scattered bones between the ancient tombs since mummies were transported. In one of the tombs, archaeologists discovered almost 400 isolated human fossils including feet, hands and teeth.

"Though many individuals were broken apart, others were left intact," Jennings noted in the book. "People were moved around the tombs, but they sometimes remained bunched together, and even earth or rocks were used to separate some groups and individuals."

Several of the grave merchandises were shattered, while other goods were left undamaged, he added.

In an interview, Jennings confirmed to LiveScience that it remains a challenge to understand the selective wrecking of the artifacts and mummies.

"In the Andes, death is a process, it's not as if you bury someone and you're done," he said.

The handling of the remains - from relocating the mummies to breaking the corpses apart - may have signified equality and a sense of community.

"The breakup of the body, so anathema to many later groups in the Andes, would have been a powerful symbol of communitas (a community of equals)," wrote Jennings in his book. This theory might clarify why some corpses were mutilated, but it is still not clear why the other bodies were left unspoiled, Jennings said.

Aside from the tombs filled with mummies, Tenahaha had many stockrooms and also communal social places where the local villagers could share food. The larger area around Tenahaha underwent ages of conflict between several villages. The site could have been a sort of neutral land where the natives could live in peace.