Medieval ruins of what archeologists believe may have been a 15th century hospital have been discovered in the grounds of Delapre Abbey.
The stone structure was uncovered beneath part of a courtyard by workers during the ongoing £6.3 million renovation project at the abbey.
Retained archaeologists, Iain Soden Heritage Services Ltd, were called in along with the county archaeologist and they confirmed the find could be removed.
But the floor structure – originally planned to be poured as a concrete slab – has been changed so that the architectural find could be preserved in place.
Councillor Tim Hadland, Northampton Borough Council’s Cabinet member for Regeneration, Enterprise and Planning, said: “The flooring will now be pre-cast concrete, so the medieval section of building can remain where it is for future generations to rediscover.
“The archaeologists believe it was either the eastern side of the abbey cloister, or the remains of an infirmary detached from the main building.
“During their investigations they discovered a type of decorative tile used extensively during the period, which helped date the find.
“There was also a circular well which would have been linked with the first floor of the building, rather an innovation for the time.”
The find also includes a basement structure, lined throughout with clay as a waterproofing medium.
Mr Soden said: “While we archaeologists regularly excavate important remains, we rarely see opportunities taken like this to preserve remains in the ground by way of sympathetic foundations.
“This is to the great credit of Northampton Borough Council and their partners at Delapre that such a preservation strategy is being put in place.”
Work on the Delapre Abbey renovation project started in March this year and is expected to conclude next summer. The Heritage Lottery Fund pledged £3.65 million for the work and the rest is made up of contributions from Northampton Borough Council and a variety of other sources.
Delapre Abbey Preservation Trust (DAPT) is currently helping oversee the project and will take operational control of the abbey on completion.
DAPT director, Rachael Boyd, said: “Once it’s completed, we’ll be opening the abbey to the public for the first time in 900 years.
“We’ll be sharing the fascinating stories of the building and its owners and creating a compelling new visitor attraction for Northampton.“