A researcher at UCD has found one of Dublin's "lost" medieval castles "hiding in plain sight" on the university's Belfield campus.
The Norman castle of Roebuck was long believed to have been cleared away when the present Roebuck Castle was built on the modern day campus site about 150 years ago.
Professor Tadhg O'Keeffe, a specialist in medieval architectural history at UCD School of Archaeology, has revealed in a new publication that the walls of the old castle are preserved inside the present Roebuck Castle.
In research published in published in Archaeology Ireland magazine, Prof O'Keeffe notes that the medieval features of the old castle are still there hidden under plaster.
"From the outside, the present building looks to be entirely Victorian. Inside, though, the walls of the old castle are preserved.
"The medieval features are still there. They’re hidden under plaster, but they can be made out.
"We are incredibly lucky that the Georgian and Victorian modernisers of the property simply built around the medieval castle rather than demolish it.
"And we are also lucky that they built very little else on the site. The courtyard at the back of the house today is actually the medieval castle courtyard."
Built in the early 13th century, the Norman castle was an important fortress on one of the approach roads into the medieval city of Dublin.
King James II of England was reputed to have lived in the castle in 1689 after he was deemed to have forfeited the throne.
The castle fell into ruin by the 18th century.
However, it was depicted by Dutch artist Gabriel Beranger around 1765.
"Beranger’s depictions of the ruined castle are really fascinating," Prof O'Keeffe said.
"He captured the basic form of the building, as you would expect, but thankfully he also captured some of those small details which are the clues needed to work out the building’s structural history."
Many medieval castles were demolished in the 17th century with their stonework being recycled for more modern premises.
It was assumed that the Norman castle at Roebuck met a similar fate until Prof O'Keeffe's latest research.
"UCD can now claim to have the oldest standing building on any university campus in Ireland," Prof O'Keeffe said.
Prof O'Keeffe is confident that the oldest part of the castle dates back to the early 13th century.
"The passage of time has been unkind to the castles which were built across south Dublin in the Middle Ages.
"Lost buildings are lost historical records. They leave gaps in our knowledge.
"It is wonderful to be able to welcome back Roebuck’s medieval castle, and to know that it won’t get lost again."