A chance discovery of coins has led to the bigger find of a Roman town, further west than it was previously thought Romans had settled in England.
The town was found under fields a number of miles west of Exeter, Devon.
Nearly 100 Roman coins were initially uncovered there by two amateur archaeological enthusiasts.
It had been thought that fierce resistance from local tribes to Roman culture stopped the Romans from moving so far into the county.
Sam Moorhead, national finds adviser for Iron Age and Roman coins for the PAS at the British Museum, said it was one of the most significant Roman discoveries in the country for many decades.
"It is the beginning of a process that promises to transform our understanding of the Roman invasion and occupation of Devon," he explained.
After the coins were unearthed by the local men out using metal detectors, Danielle Wootton, the University of Exeter's liaison officer for the Portable Antiquities Scheme (PAS), which looks after antiquities found by the public, was tasked with investigating further.
After carrying out a geophysical survey last summer, she said she was astonished to find evidence of a huge landscape, including at least 13 round-houses, quarry pits and track-ways covering at least 13 fields, the first of its kind for the county.
"You just don't find Roman stuff on this scale in Devon," said Ms Wootton.
She carried out a trial excavation on the site, and has already uncovered evidence of extensive trade with Europe, a road possibly linking to the major settlement at Exeter, and some intriguing structures, as well as many more coins.
"This was a really exciting discovery," said Ms Wootton. But she said most exciting of all was that her team had stumbled across two burial plots that seem to be located alongside the settlement's main road.
"It is early days, but this could be the first signs of a Roman cemetery and the first glimpse of the people that lived in this community," she explained.
Romans in Devon
Not enough excavation has been done yet to date the main occupation phase of the site, but the coins that were found range from slightly before the start of the Roman invasion up until the last in 378AD.
The Romans reached Exeter during the invasion of Britain in AD 50-55, and a legion commanded by Vespasian built a fortress on a spur overlooking the River Exe. This legion stayed for the next 20 years before moving to Wales.
A few years after the army left, Exeter was converted into a bustling Romano-British civilian settlement known as Isca Dumnoniorum with all the usual Roman public buildings, baths and forum.
It was also the principal town for the Dumnonii tribe, a native British tribe who inhabited Devon and Cornwall. It was thought that their resistance to Roman rule and influence, and any form of 'Romanisation' stopped the Roman's settling far into the south west.
For a very long time, it was thought that Exeter was the limit of Roman settlement in Britain in the south west, with the rest being inhabited by local unfriendly tribes.
Some evidence of Roman military occupation has been found in Cornwall and Dartmoor, thought to be protecting supply routes for resources such as tin.
However on this site, more than just the coins are Roman. Pottery and amphora fragments recovered suggest the town embraced trading opportunities in Europe that came with Roman rule, and a fragment of a Roman roof tile has also been found.
Danielle Wootton received some funding from the British Museum, the Roman Research Trust and Devon County Council in June to carry out the trial excavation but said more money was needed as they still had not reached its outer limits.
"We are just at the beginning really, there's so much to do and so much that we still don't know about this site.
"I'm hoping that we can turn this into a community excavation for everyone to be involved in, including the metal detectorists," she explained.
Sam Moorhead said he believed more Roman settlements may be found in the area in the next few years.
The excavation of this unique site will feature in the forthcoming BBC Two series Digging For Britain.