The survey has produced the clearest plan of the town yet seen confirming the street plan (shown by previous aerial photographs), the town's water supply system (detecting the iron collars connecting wooden water pipes), and the series of public buildings including the baths, temples and forum, known from earlier excavations.

However, the survey also showed that earlier interpretations of the town as a densely occupied urban area — given by reconstruction paintings — may be totally wrong. Buildings were clustered along the main streets of the town, but other areas within the street grid seem to have been empty and were perhaps used for grazing or cultivation.

Dr Bowden, a lecturer in Roman Archaeology, said: "The results of the survey have far exceeded our expectations. It's not an exaggeration to say that the survey has advanced our knowledge of Caistor to the same extent that the first aerial photograph did 80 years ago.

“The presence of possible Iron Age and Saxon features suggests that the town had a much longer life than we previously thought and the fact that it's just sitting there in open fields instead of being under a modern town means we can ask the questions we want to.

“For an archaeologist it's a dream opportunity to really examine how European towns developed."

A new Roman theatre?

One of the most exciting new discoveries from the survey is what looks like a Roman theatre. Clear traces of a large semi-circular building have been found next to the town's temples — the typical location for a theatre in Roman Britain.

David Gurney, Principal Archaeologist of Norfolk Museums & Archaeology Service, said: “This is a fantastic discovery, and it goes to show that Caistor Roman town still has a great number of secrets to be disclosed in the years ahead through surveys or excavations.

“The town is already well-established as the most important Roman site in northern East Anglia, but the presence of a theatre is a significant indicator of the town's status, and of the cultural facilities available to its inhabitants.

“It is brilliant that the project has located such an important feature so early on, and this is probably just the first of many discoveries that will completely change our understanding of the town as a result of the Caistor Project.”

Matthew Martin, Chairman of the Norfolk Archaeological Trust, which owns the Roman town, said: "We are delighted with all the work which Dr Bowden and his team are carrying out at Caistor. We are very excited not only by what has been discovered so far by the use of this new technology but by the possibilities for more discoveries as further work is done.

“I think that all this is of immense interest to not only archaeologists but to a much wider public.”

Discoveries from the age of Boudica?

Caistor lies in the territory of the Iceni, the tribe of Boudica who famously rebelled against Roman rule in AD 60/61. The survey revealed numerous circular features that apparently predate the Roman town.

These are probably of prehistoric date, and suggest that Caistor was the site of a large settlement before the Roman town was built. This has always been suspected because of numerous chance finds of late Iron Age coins and metalwork, but there has never been any evidence of buildings until now.

Now the burning questions are: was Caistor built on the site of an Iceni stronghold as retribution after Boudica's rebellion, or was it built to favour a faction of the Iceni who had not taken part in the revolt?

The end of a Roman town?

Life at Roman Caistor was thought to have ended in the 5th century AD, when Britain was abandoned by the emperor of the struggling Western Roman Empire.

However, the new survey clearly shows a large ditched enclosure that cuts the surface of the Roman street in the north-west corner of the site. Possible structures are visible within this enclosure.

The earlier discovery of middle Saxon coins and metalwork outside the west wall of the site, combined with the presence of two early Saxon cemeteries in the vicinity suggests that these enclosures may be associated with continued life in the town after the Roman period.

The new research has demonstrated that Caistor is a site of international importance.

Rather than simply being a provincial Roman town, Caistor may represent the development of a major settlement from the Iron Age until the 9th century AD. Crucially, however, the site was ultimately superseded by medieval Norwich and reverted to green fields.

This is quite unlike other Roman towns that have the same long occupation sequence which now lie buried beneath the modern towns of Britain and Europe.

This fortunate change of settlement location means that these same green fields at Caistor are a unique time-capsule that could give us vital clues to the complex processes through which our towns and cities developed. Funding is now being sought to test the results of the survey through excavation.

More details of the site are available at: www.south-norfolk.gov.uk/venta

— Ends —

Notes to editors:

Images are available on request from Martin Kirk, Audio-Visual Officer in the Communications Office, University of Nottingham, 0115 846 7377, or email martin.kirk@nottingham.ac.uk

The site of Caistor Roman town is a Scheduled Ancient Monument owned by the Norfolk Archaeological Trust and managed by South Norfolk Council.

The Caistor Roman Town Project is sponsored by South Norfolk Council, the British Academy, The University of Nottingham, the Norfolk Museums & Archaeology Service, the Society for the Promotion of Roman Studies and the John Jarrold Trust.

The University of Nottingham undertakes world-changing research, provides innovative teaching and a student experience of the highest quality. Ranked by the Times Higher in the world's Top 70 universities, its academics have won two Nobel Prizes since 2003. The University is an international institution with campuses in the United Kingdom, Malaysia and China.

More information is available from Dr Will Bowden, Department of Archaeology, University of Nottingham on +44 (0)115 951 4830, mobile +44 (0)7733 104737, will.bowden@nottingham.ac.uk; Media Relations Manager Tim Utton in the University's Communications Office on +44 (0)115 846 8092, tim.utton@nottingham.ac.uk; or David Peel, Communications Manager, South Norfolk Council, on +44 (0)1508 533611 or

dpeel@s-norfolk.gov.uk.