Rare Roman remains discovered at a housing development in Scarborough are believed to be the first of their kind in Britain and possibly the entire ancient Roman empire.
Archaeological excavations uncovered the remains at the development in North Yorkshire, which has now been redesigned to conserve the find.
Historic England are set to recommend that the large complex of buildings found at the Eastfield site is protected as a nationally important scheduled monument.
Housing developer Keepmoat Homes employed archaeologists to carry out excavations at the site, which was suspected of containing Iron Age and Roman remains.
A spokesman for Historic England said the Roman remains uncovered were more significant than anticipated with the complex including a circular central room, with several rooms leading off it, and a bath house.
Archaeologists believe the remains are likely to represent a high-status luxury Roman villa or religious sanctuary, or a combination of both.
The spokesman said: "This type of building layout has never been seen before in Britain and could even be the first of its kind to be discovered within the whole former Roman Empire."
Historic England will grant aid for the additional archaeological work, which will include the analysis and publication of discoveries made at the site.
Keith Emerick, the inspector of ancient monuments at Historic England, said: "These archaeological remains are a fantastic find and are far more than we ever dreamed of discovering at this site.
"They are already giving us better knowledge and understanding of Roman Britain.
"We are grateful to Keepmoat Homes for their sensitive and professional approach to helping ensure the future conservation of this important historical site."
Karl Battersby, corporate director, business and environmental services at North Yorkshire County Council, said: "This is a remarkable discovery, which adds to the story of Roman settlement in North Yorkshire.
"Work by North Yorkshire archaeologists has already established the buildings were designed by the highest-quality architects in Northern Europe in the era and constructed by the finest craftsmen.
"Because of the significance of this, it is excellent to see that the layout of the new housing has been redesigned so this important part of our history can be preserved.
"There will be further work on the finds and environmental samples to try to establish exactly what this enigmatic site was and why it was created so far from other Roman centres."