Archaeologists on Orkney are investigating what is thought to be a 5,000-year-old tomb complex.
A local man stumbled on the site while using a mechanical digger for landscaping.
It appears to contain a central passageway and multiple chambers excavated from rock.
There is a large neolithic burial complex nearby called The Tomb of the Eagles where over 300 bodies were found.
"Potentially these skeletons could tell us so much about Neolithic people," said Orkney Islands Council archaeologist Julie Gibson.
"Not only in relation to their deaths, but their lives."
One end of the tomb was accidentally removed as it was discovered and as a result, the burial site has now been flooded.
Archaeologists are in a race against time to recover its contents before they are damaged or destroyed.
"There might also be other material, pottery or organics such as woven grass, buried in there - which cannot last under the circumstances," said Ms Gibson.
The rescue excavation is being undertaken by archaeologists from Orkney College and is sponsored by Orkney Islands Council and Historic Scotland.
The team are posting daily video updates from the excavations which are expected to take 10 days.