Archaeological investigations by Bradley and colleagues in 1986 revealed that the castle had a substantial presence along North Main Street, with a 19-metre frontage and extending 9 metres back from the street. The castle grounds included additional back premises and a walled rear garden, suggesting it was a significant property in medieval Naas.

While the original castle has long since vanished, some tantalising traces may remain. Historian Ben Murtagh, writing in the early 1980s, noted that certain walls behind the current Town Hall appear to predate 1700, though none can be definitively linked to the castle itself. These fragments serve as a reminder of the layers of history beneath modern Naas, where centuries of development have obscured but not entirely erased the medieval townscape.

The transformation from White Castle to Town Hall reflects the changing fortunes of Naas over the centuries. Once a fortified settlement requiring defensive structures, the town evolved into an administrative centre where civic buildings replaced military ones. Today, visitors to the Town Hall might walk past without realising they're standing where a castle once commanded this stretch of North Main Street, its walls and gardens forming part of the medieval fabric that shaped modern Naas.