Archaeologists have uncovered a medieval Irish castle that was thought to have been lost forever. Located on the campus of University College Dublin (UCD), the Roebuck Castle exhibits architecture typical of the 19th century. However, for centuries, precious remnants of a 13th-century Irish castle had been waiting on the site. The structure discovered has become the oldest building in Ireland located on a university campus. Sources indicate that the building was constructed in the context of the Norman invasion of Ireland. This suggests it was built shortly after 1169. Since then, it has undergone many transformations. Throughout its history, the castle is said to have hosted an Irish chancellor. According to local tradition, James II, King of England and Ireland, is said to have stayed there after his deposition in 1689. Fallen into ruins in the 18th century, historians thought it had been demolished to make way for new construction. However, the artist Gabriel Beranger visited the ruins around 1765. He then created a series of watercolors depicting its structure. "He captured the general form of the building, as one might expect, but fortunately, he also depicted some small details that constitute necessary clues to reconstruct the structural history of the building," explains Tadhg O'Keeffe, a medieval architecture specialist at UCD. Under the Victorian style, medieval remnants Tadhg O'Keeffe and his team discovered walls and other elements of the Norman Roebuck Castle under the layers of plaster of the modern structure. "The medieval elements are still there," the researcher specifies. They are simply hidden by constructions made centuries later. This discovery contradicts theories that the Norman building had completely disappeared. Once, where the university campus now stands, there was a fortress near the road leading to Dublin. The research has shown that the architectural remains have the characteristics of a building dating back to the 13th century. The professor notes that the courtyard located behind the current building "is actually the courtyard of the medieval castle." It is all the more impressive that the subsequent transformations preserved the original part, building around it. "We also have the luck that they built very little else on the site," he adds. The team recalls that very few medieval castles located south of Dublin have survived over the centuries. Many were destroyed or looted in the 17th century. Some stones were later reused for other houses. According to Tadhg O'Keeffe, the disappearance of these buildings leaves gaps in the understanding of the region's history.