Richards’ 1691 map of the town reveals a fascinating detail: three “Old Castles” once stood on the southern side of what’s now The Square, at the western end of Main Street (today’s Oliver Plunkett Street). These structures were part of a larger collection of castle buildings that once dominated the town’s architecture, serving as both defensive structures and residences for Mullingar’s medieval elite.

Writing in 1682, Sir Henry Piers painted a vivid picture of Mullingar’s transformation from a fortified settlement to a more modern town. He noted that the ancient buildings were “old fashioned castles”, some of which still stood in his day whilst others had been demolished to make way for “better or at least more commodious houses”. This observation captures a crucial moment in Irish urban development, when the military architecture of earlier centuries was giving way to the domestic comforts demanded by a more peaceful era. At least six castle sites have been identified within the historic town boundaries, though their exact locations remain somewhat elusive.

Despite extensive surveys and archaeological investigation, no visible traces of the three castles shown on Richards’ map can be found in The Square today. The precise spots where these fortifications once stood have been lost to centuries of urban development, leaving historians and archaeologists to piece together their story from old maps and written accounts. The 1992 Irish Historic Towns Atlas of Mullingar meticulously documents these phantom structures, labelling them as “Building D” on their reproduction of Richards’ map, ensuring that whilst the stones may have vanished, the memory of Mullingar’s castellated past endures.