Darver Castle stands as a remarkable four-storey fortress in County Louth, built from uncoursed limestone rubble and greywacke that has weathered centuries whilst remaining occupied to this day.

In the townland of Corbollis, County Louth, historical maps tell the story of a vanished castle that once stood as a prominent landmark.

In the rolling countryside of County Louth, the site of Mullanstown Castle offers a glimpse into Ireland's layered past, though visitors today will find little more than a disused quarry pit where this structure once stood.

Darver Castle stands on the northwest side of what was once a fortified bawn, though today only fragments of this defensive enclosure survive.

Behind Piedmont House in County Louth stands a curious remnant of Ireland's turbulent past: the ruins of an old bawn wall, complete with two gun loops facing east.

The remains of what appears to be a medieval motte once stood on a gentle rise near the north bank of the River Fane in Stephenstown demesne, County Louth.

In the low-lying ground near the western bank of the Ballymascanlan River stand the weathered remains of what was likely once a formidable late medieval tower house.

In the borderlands between ancient baronies in County Louth, the Down Survey maps of 1656-8 mark a castle at Hurlestowne, number 63 in the parish of Smermer.

Standing dramatically on a rocky outcrop that falls away sharply on all sides except the east, Roche Castle commands the Louth countryside with medieval authority.

Aerial photography has revealed an intriguing medieval site at Dellin, County Louth, where cropmarks clearly show the outline of an oval enclosure measuring approximately 65 to 70 metres at its widest point.

Standing just outside the old town walls of Ardee in County Louth, this sturdy medieval tower house cuts an imposing figure despite its current use as a farm building.

Haynestown Castle stands as a compact, almost square fortress in County Louth, distinguished by its unusual construction method and four corner towers.

This modest tower house in Carstown, County Louth, stands as a compelling example of late medieval Irish defensive architecture, though it has been considerably altered over the centuries.

Standing three storeys high in the County Louth countryside, Glaspistol Castle is a formidable limestone and greywacke tower house that showcases the defensive architecture of medieval Ireland.

Perched on a gentle rise overlooking the River Dee, the imposing earthwork known as Dawson's Moat has puzzled historians for centuries.