What is the oldest-known archaeological site in the world?

Our human ancestors were roaming Earth as far back as 6 million years ago, but what is the earliest site containing archaeological evidence of their existence? 

It turns out, there are two spots — one in Kenya and the other in Ethiopia — that are considered the top candidates for world's oldest archaeological sites, according to about a dozen scholars, all with expertise in prehistoric archaeology and anthropology, who spoke with Live Science. 

The question of what is the oldest archaeological site in the world is "a topic that has since recently divided the archaeological community," Yonatan Sahle, a senior lecturer of archaeology at the University of Cape Town in South Africa, told Live Science in an email. 

Related: The 25 most Mysterious archaeological finds on Earth

The first site, called Lomekwi 3, holds bones of hominins as well as stone artifacts and is located on a low hill in West Turkana, Kenya. In a study published in 2015 in the journal Nature, researchers reported that, by dating the sediment where the artifacts were found, they estimated the age of the site to be about 3.3 million years. The finds "mark a new beginning to the known archaeological record," a team of scientists wrote in the journal article. The tools were likely created by Australopithecus afarensis, a hominin (human ancestors and their relatives) that thrived in the region at the time. 

The site is located in a wooded area on a small hill not far from Lake Turkana. It's possible that Australopithecus afarensis was using the stone artifacts to break open nuts the team wrote in the paper. The number of people who lived at the site at any given time is not clear. 

"Lomekwi 3 is the oldest known archaeological site in the world," Jason Lewis, assistant director of the Turkana Basin Institute and a co-author of the paper, told Live Science in an email.