One of Leicestershire's most important archaeological monuments is being excavated for the first time in nearly 40 years.
Trenches are being dug up in the Iron Age hill fort at Burrough on the Hill near Melton Mowbray in the hope of finding clues about life from 600BC.
The site was opened to the public on Sunday.
Site directors said hill forts were enigmatic monuments which had rarely been scientifically excavated.
Similar work had been carried out on the Burrough Hill site on a much smaller scale in the 1950s and 1960s.
Recent excavations have already revealed part of stone defences of the hill fort entrance, along with a cobbled road and timber gateway.
A second trench has revealed many Roman finds, suggesting the site had remained significant for nearly 800 years.
The work has been undertaken by scientists from the University of Leicester after English Heritage gave the go-ahead.
Dr Patrick Clay, of University of Leicester Archaeological Services, said a lot of information about the Iron Age in Leicestershire had been discovered over the past 20 years through examining small farmstead and larger undefended settlements.
He said: "The big gap in our knowledge has been how these large defended 'hill forts' fitted into the picture.
"Did they serve as market centres for surrounding farms or were they a tribal leader's capital - or both? This work may help to provide some of the answers."