Recent excavation finds evidence of a settlement thought to date back 6,500 years.
Archaeologists from the UK and France were in Herm in September '25 to further examine its megalithic past.
A team supported by the French Ministry of Europe and Foreign Affairs has been studying two sites on the Common.
One, the tombstone at Robert's Cross, has been extensively excavated over the years, but the team were again impressed by the sheer size of the rocks used to create the burial chamber.
Samples have been sent for analysis to find out when the tomb, which is around 6 thousand years old, collapsed.
Nearby, an area by the path to Bear's Beach has been dug up, which suggests farming was active on the Common 6,500 years ago.
The experts say post holes for Neolithic houses suggest a population that pre-dated the tomb building period.
More excavations are planned for next year.
New pontoons in St Peter Port Harbour
Guernsey's latest crime trends revealed
Man arrested over 'threats to kill' in Guernsey
Jersey and Guernsey both lift trophies in Siam and Muratti weekend
Men pretending to be police arrested for £10K Guernsey convent fraud
Channel Islands' 10 wealthiest residents revealed
85 home planned for Forest site in Guernsey
Sewage outfall failure on Guernsey's east coast
