Richards’ 1691 map of the town clearly marks three ‘Old Castles’ on the southern side of The Square, though their precise locations have proved frustratingly elusive to modern historians. By the time the Ordnance Survey mapped the area in 1837, these formidable structures had vanished so completely that cartographers could only mark the spot as ‘Site of Castle’, acknowledging what had been lost to time and progress.

These vanished fortifications were part of a broader network of defensive structures that once bristled throughout medieval Mullingar. Writing in 1682, Sir Henry Piers noted that the town still retained several ‘old fashioned castles’, though even by his time some had already been demolished to make way for what he considered ‘better or at least more commodious houses’. His account suggests at least six castle sites scattered across the historic town centre, painting a picture of Mullingar as a heavily fortified settlement where tower houses and castles were as common as market stalls.

Today, visitors to The Square will find no trace of these once-imposing structures; no tumbled stones or grassy mounds hint at their former presence. The castles that once guarded Mullingar’s western approaches have been so thoroughly erased that only old maps and written accounts confirm they ever existed at all. It’s a reminder of how completely Ireland’s medieval urban landscape has been transformed, with centuries of rebuilding, redevelopment and modernisation sweeping away the physical remnants of the town’s defensive past.