Scottish Water was carrying out the works at Philiphaugh on the outskirts of Selkirk whilst laying new pipes between Howden and Yarrowford.
A Scottish Borders Council's archaeologist said:
"It is an exciting discovery. It is not every day that medieval villages are found - most of them are known, this one was completely unknown."
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Mainly dry until later on Wednesday. A cooler, showery and blustery end to May
Mainly dry. Light rain out of thicker cloud over hills. Breezy at times and cooler than average
A look ahead at the forecast for the Border region.