An early neolithic village has been uncovered by archaeologists in Orkney.
The discovery at Smerquoy shows ancient island farmers lived in settlements rather than in isolated farmsteads, as historians previously believed.
The unexpected find was made following three years of fieldwork at the long-lost settlement near Kirkwall.
Professor Colin Richards, of Manchester University, who specialises in neolithic Orkney, said: "What makes this an exciting discovery is that we appear to be excavating within a substantial early neolithic village where houses are situated in a row next to one another along the side of the hill.
"Each house is terraced into the hill slope in order to provide a level internal floor surface.
"These are large houses, with floor areas of around 50 square metres subdivided into inner and outer rooms or compartments. These were large, comfortable houses."
Prof Richards said the formation of villages at such an early date suggests there was a "substantial influx" of people to the northern isles at that time.
He added: "The discovery of an early Neolithic village at Smerquoy confirms the results obtained from the interesting sites of Ha'Breck, Wyre and Stonehall near Finstown.
"At both these sites, several early Neolithic houses were discovered but whether they formed a village like that seen at the later Skara Brae was debatable.
"Indeed, it was not such a long time ago that many archaeologists thought the first farmers dwelt in small isolated farmsteads, like that seen at Knap of Howar, Papay."
Meanwhile, a team of archaeologists began a search for evidence of the Roman army in Angus on Monday.
The Romans built a number of outposts in northern Scotland, including the world's most northerly Roman fort at Stracathro, but their purpose is unclear.
The team, led by Andrew Tibbs of Durham University, hope finding new military sites in the north east might help solve the mystery.