Richards’ 1691 map of the town reveals an intriguing detail: an ‘Old Castle’ marked on the north side of Church Lane, sitting northwest of the medieval parish church. While the exact location of this fortification remains elusive to modern archaeologists, some suggest the later vicarage may have been constructed atop its foundations, quite literally building the new upon the old.

This mysterious castle was one of several defensive structures that once dotted Mullingar’s landscape. Writing in 1682, Sir Henry Piers painted a picture of a town in transition, noting that Mullingar contained ‘ancient buildings here [that] were old fashioned castles, some of which remain yet, and some are demolished, and better or at least more commodious houses are built in their room’. His account suggests at least six such castles once stood within the town boundaries, though by his time, the medieval military architecture was already giving way to more comfortable domestic dwellings.

The Richards map provides a tantalising glimpse of late 17th century Mullingar, showing the castle positioned within the town’s star-shaped fortifications. Marked as Building D amongst the ‘Old Castles’, it stood in close proximity to All Saints’ Parish Church, suggesting its importance in the town’s medieval hierarchy. Though the physical structure has long since vanished, its presence on historical maps continues to inform our understanding of Mullingar’s evolution from a fortified medieval settlement to a more modern market town.