Mysterious giant 300,000-year-old hand axes were found at an Ice Age site in England. Scientists can't work out why they are so big.

• Two giant hand axes have been uncovered in prehistoric sediment in England.
• The tools, which are more than 300,000-year-old, are so big they are difficult to handle.

Two giant prehistoric hand axes, one of which is about a foot long, have been uncovered in deep Ice Age sediments in the south of England.

The 300,000-year-old tools, slabs of flint chipped on both sides to create jagged edges, were found among than 800 artifacts buried on a hillside above the Medway Valley in Kent.

"We describe these tools as 'giants' when they are over 22cm long and we have two in this size range," senior archaeologist Letty Ingrey of the UCL Institute of Archeology said in a press release.

The largest of the two hand axes, which is about 12 inches long, is "one of the longest ever found in Britain," said Ingrey, who participated in the excavation.

Archaeologists think these types of tools were typically used to butcher or skin animals.

But these particular hand axes "are so big it's difficult to imagine how they could have been easily held and used," Ingrey said.

"Perhaps they fulfilled a less practical or more symbolic function than other tools, a clear demonstration of strength and skill," she said.

At the time, the Medway Valley site would have been a prime hunting ground roamed by deer, horses, as well as now-extinct straight-tusked elephants and lions that lived in the area, per the press release.

Early humans would have shared the landscape with Neanderthals whose peoples and cultures were just beginning to emerge in the area, per the press release.

"Right now, we aren't sure why such large tools were being made or which species of early human were making them," said Ingrey.

"This site offers a chance to answer these exciting questions," she added.