Early human occupation of the site dates back to Celtic tribes.
Roman culture had a profound effect on the Celtic tribes which came under the empire's control.
The first settlers were probably from the Celtic tribes.
Once the Celtic tribes there were as free as the rest of us.
But the Celtic tribes of the western island did not call themselves by that Roman name.
The area is in fact named after an ancient Celtic tribe called the "serdi".
It concerns the armed conflicts of the Celtic tribes and their kingdoms.
According to the earliest records, the area was settled by culturally Celtic tribes.
About 4,000 years ago, Celtic tribes made special journeys here, evidently to practice religious rites.
The mine has been worked for over 7,000 years since the time of the Celtic tribes and earlier.