Some 800 prehistoric stone artefacts thought to be 300,000 years old have been discovered on the site of a new school.
Excavations revealed the findings in deep Ice Age sediments found preserved on a hillside in Frindsbury near Strood.
The excavations took place in advance of the building of the new Maritime Academy, which will now look at how to use the discoveries in its curriculum.
Among the unearthed artefacts are two “spectacular” large flint knives described as “giant handaxes”.
Researchers believe this type of tool may have been used for butchering animals and cutting meat.
Senior archaeologist at University College London’s Institute of Archaeology, Letty Ingrey, said they were unsure on why such large tools were made.
She said: “These handaxes are so big it’s difficult to imagine how they could have been easily held and used.
“Perhaps they fulfilled a less practical or more symbolic function than other tools, a clear demonstration of strength and skill.
“While right now, we aren’t sure why such large tools were being made, or which species of early human were making them, this site offers a chance to answer these exciting questions.”
These two handaxes have a distinctive shape with a long and finely worked pointed tip, and a much thicker base.
While archaeological finds of this age have been found in the Medway Valley before, this is the first time they have been found as part of large-scale excavation.
The research suggests the site dates back to a period when Neanderthal people were beginning to emerge.
During this period the are would have been a wild landscape of wooded hills and river valleys, inhabited by red deer and horses, as well as the now-extinct straight-tusked elephant and lion.
The institute’s Dr Matt Pope said how important the handaxes are in the study of Ice Age Britain.
He said: “The excavations have given us an incredibly valuable opportunity to study how an entire Ice Age landscape developed over a quarter of a million years ago.
“A programme of scientific analysis, involving specialists from UCL and other UK institutions, will now help us to understand why the site was important to ancient people and how the stone artefacts, including the ‘giant handaxes’ helped them adapt to the challenges of Ice Age environments.”
The research team is working on identifying and studying the recovered artefacts to better understand who created them and what they were used for.
Meanwhile, senior archaeologist Giles Dawkes is leading work on a second significant find from the site – a Roman cemetery, dating to at least 250,000 years after the Ice Age activity.
The people buried there between the first and fourth centuries AD could have been the inhabitants of a suspected nearby villa.
The team found the remains of 25 individuals, 13 of which were cremated. Nine of the buried individuals were found with goods or personal items including bracelets, and four were interred in wooden coffins.