One of Wales' oldest farms dating back thousands of years is believed to have been discovered in a field in Ceredigion.
The north Wales Bronze Age farm may date from the time of Stonehenge
Archaeologists were called in to investigate the site near Llandysul, after workmen clearing farmland for a new Welsh Development Agency industrial estate noticed dark circles in the soil.
Cambria Archaeology workers then identified several large circular graves from the Bronze Age.
And about 200 yards away they found the foundations of a farmyard wall which could have been built 5,000 years ago.
The WDA suspended clearance work for five weeks to allow archaeologists to excavate the site.
"These finds are staggeringly exciting and of extraordinary importance," said Gwilym Hughes of Cambria Archaeological Trust, which is now two weeks into the dig.
"This farm is a missing link in the pre-history of west Wales.
"Although a number of hill forts date from this period, non-defended domestic settlements are extremely rare."
The remains of the burial mounds consist of three rings, each about 12 metres in diameter.
They are typical of burial mounds of about 2000 BC where the cremated remains of the community's elders would have been buried.
But according to Mr Hughes, the second excavation is even more exciting.
Within the pear-shaped stone enclosure are post-holes belonging to Bronze Age or early Iron Age huts.
The settlement is big enough to have contained two or three houses.
"Carbon dating should confirm that the burial mound dates to about 2000BC," said Mr Hughes.
This means the Bronze Age graveyard dates back to the time the Preseli Bluestones were raised at Stonehenge.
An extra 10 archaeologists have been taken on to find artefacts that will help to date the site accurately.
They have already found a piece of pottery containing the remains of burnt hazelnut shells.
"It is possible that the enclosure could date as far back as 3000 BC," said Mr Hughes.
"But we need to find more pottery that has decoration so we can provide a more accurate date to the site."
Farm is "missing link" in Welsh history
The WDA plan to build up to six light industrial business units on the site.
"Although Cambria believe that five weeks will be enough for them to complete their dig we will consider any extension depending on their findings," said an agency spokesman.
The results of the dig, including carbon dating tests, are expected to take two months to complete.