When a host of 130,000-year-old stone tools were initially discovered on Crete nearly a decade ago, archaeologists were at first in doubt that Stone Age civilizations could have made their way here so long ago, yet new evidence continues to flood in showing that it is actually very likely that both Stone Age people and even Neanderthals may have constructed boats and traveled to the Mediterranean.

The very earliest boat that has ever been discovered was built 10,000 years ago and was found deep in the Netherlands. But when it comes to actually confronting the ocean itself, the only evidence that archaeologists have of boats made exclusively for this purpose date to around 2,000 BC, when long voyages were made from India to Arabia, as Science Magazine reports.

With the vast majority of scientists previously of the belief that only Bronze Age civilizations took to the open sea, Brown University archaeologist John Cherry notes that today it is actually quite common to hear discussions on earlier societies like Neanderthals and Stone Age people voyaging to distant lands. Even, perhaps, the Mediterranean.

“The orthodoxy until pretty recently was that you don’t have seafarers until the early Bronze Age. Now we are talking about seafaring Neanderthals. It’s a pretty stunning change.”

Neandertals, Stone Age people may have voyaged the Mediterranean https://t.co/7hMysmdQf2pic.twitter.com/tUXIT2U3XR — PaleoAnthropology+ (@Qafzeh) April 25, 2018

While no wooden boats would have stood the test of time to show hard, physical evidence that Neanderthals and Stone Age civilizations definitively sailed to the Mediterranean, stone tools recovered from a site at Plakias in 2008 and 2009 looked exceedingly similar to tools used by Homo erectus over a million years ago. These same tools would also have been in use among Neanderthals at least 130,000 years ago as well.

Archaeologist Thomas Strasser’s argument was that Neanderthals may have sailed to Europe from the Near East, yet when soil samples were taken at the site to try to either prove or disprove the theory that these tools were at least 130,000 years of age the evidence came back inconclusive.

Since then, a plethora of other similar tools have turned up on different islands including Naxos, which is just north of Crete. Tristan Carter of McMaster University helped lead a team of archaeologists to this site, and it was discovered that hand-axes and other tools found looked almost exactly like ones that both early humans and Neanderthals would have used 200,000 years ago.

However, the biggest difficulty lies in to trying to ascertain which of these locations would have been islands at the time that these tools were in use, something that has proven challenging for archaeologists.

Yet with fresh new evidence of tools and other relics continuing to mount, archaeologists are now keeping an open mind about the possibility that Stone Age people and Neanderthals may have constructed boats and journeyed to the Mediterranean.