Marine archaeologists have discovered a Stone Age realm sunk beneath the Solent.
Evidence of human habitation was excavated last week from under a drowned oak forest of fallen tree trunks and stumps that once stretched from the Isle of Wight to the mainland.
It is the first time such ancient remains have been found stratified off of the coastline of the United Kingdom, although a number of similar sites have been explored on dry land.
Archaeologists from the Hampshire and Wight Trust for Maritime Archaeology, based at the Southampton Oceanography Centre, found flints and pieces of charcoal under an 8,500-year-old layer of peat, 11 metres below sea level.
The relics were brought to the surface during eight days of diving in the Solent's murky waters.
Garry Momber, the trust's archaeological officer, said: "It appears we have evidence of a hearth and flint working in the vicinity of a middle Stone Age camp site. Nothing like this has been found off the coast of the British Isles."
The experts had known of the submerged oak forest at the foot of an underwater cliff in the Solent for 20 years. But the discovery of flint fragments, quarried by a lobster in the course of digging its burrow, alerted them to the possibility that remains of human occupation might also be there.
The divers brought blocks of the peat and silt from about a square metre of sea bed to the surface during the excavation. The contents are still being analysed.
Mr Momber said there were signs of fires, including burnt flints and small pieces of charcoal. There were also numerous flint flakes from tool making.
It is probably a spot where a group of hunter-gatherers from the middle Stone Age sat around a campfire working flint in the valley between the mainland and what is now the Isle of Wight at the time that the first civilisations were rising in the Near East.