An exploration of the highest altitude archaeological site in the world could provided insight into how humans adapt to extreme environments.

The Cuncaicha site, located in the Peruvian Andes, is about 14,698 feet above sea level; there is also a Pucuncho workshop site where stone tools were made at only a marginally lower altitude, the University of Calgary reported.

These sites had brutal climate conditions such as "low-oxygen, extreme cold and high levels of solar radiation," but it appears people still managed to live here for extended periods of time between 12.4 and 11.5 thousand years ago.

"We don't know if people were living there year round, but we strongly suspect they were not just going there to hunt for a few days, then leaving," said University of Calgary archaeologist Sonia Zarrillo. "There were possibly even families living at these sites, because we've found evidence of a whole range of activities."

The fascinating sites boast ancient skull fragments and animal bones alongside the man-made stone tools.

"Hunters passing through an area will take the meat back to campsites and leave the carcass in the field," Zarrillo said. "In Cuncaicha we found remains representing whole animals, indicating they were living close to where the animals were killed. And the types of stone tools we've found are not only hunting tools but also scraping tools used for processing hides to make things like clothing, bags or blankets."

Popular theories suggest people cannot live at high altitudes until they have genetically adapted to do so, as have modern Andean people. These individuals have "higher metabolic rate, larger lung capacity and higher hemoglobin concentrations" than average people.

Researchers are sure if these genetic adaptations had occurred in the ancient people or if they were somehow able to live at high altitudes despite the treacherous conditions.

"Research really hasn't been done here up until now, because it's so remote," Zarrillo said. "Our team hiked up to three or four hours to get to these sites. That was a climb, carrying all of our gear, camp equipment and food. And it freezes every night. Sometimes it snows. These are incredibly hard sites to access."

The findings will be published in the Oct. 23 in the journal Science.