The find is described as "an unexpected and exciting discovery"
Archaeologists working on the Quantock Hills in Somerset have uncovered evidence of a substantial Roman villa with a mosaic floor in the main room.
The findings are part of a six-year study carried out on six separate sites around the area.
The dig team said the villa at Yarford is one of the most westerly villas with mosaic floors found in Roman Britain.
It was subjected to three seasons of excavation but has since been buried again to protect it for the future.
The excavation was jointly carried out by the University of Winchester, Somerset County Council and English Heritage.
Dr Keith Wilkinson, from Winchester University, said: "This was an unexpected and exciting discovery and was an important and significant site on this part of the Quantock Hills.
"If there is one villa, then the chances are that others will be found in due course."
Also discovered at the Yarford dig is a large prehistoric site dating from the Iron Age around 500 BC.