Though the 1839 Ordnance Survey map confidently labels this spot in gothic lettering as a castle site, no physical trace of the structure remains today. The location sits just north of an ancient moated site, with a church about 50 metres to the east, suggesting this was once the heart of a small medieval settlement at Mountpleasant.

The Rochford family held sway over Tagunnan from the early 14th century, establishing themselves as prominent local gentry. By 1608, Hugh Rochford of Tagunnan appeared on the rolls as one of the county's gentlemen, controlling 131 acres by 1641. This same Hugh Rochford would go on to serve as county sheriff and lead rebel forces during the siege of Duncannon Fort, marking him as a significant figure in the Confederate Wars. His son later served Charles II during his continental exile, though despite this royal connection, he couldn't reclaim the family's Tagunnan lands after they were granted to the Knox family during the Cromwellian confiscations of the 1650s.

The Down Survey map from 1656–8 provides our best glimpse of what once stood here, depicting Tagunnan Castle as a tower house with an attached domestic building and two small cabins nearby. This arrangement was typical of Irish tower houses of the period, where the fortified tower served both defensive and residential purposes whilst additional buildings housed servants, stored supplies, or provided extra living space for the extended household. Today, visitors to the site must rely on imagination to conjure the castle that once commanded this quiet corner of Wexford.