This National Monument, protected as No. 323 under state ownership, consists of a rectangular two-storey hall measuring 21 metres east to west and nearly 10 metres north to south. Built from roughly coursed limestone and felsitic rubble, the structure retains its northern wall largely intact, complete with defensive towers at both corners. The northwestern tower still preserves fascinating medieval features including a cross-loop window, multiple garderobe chutes, and an internal chamber, whilst a stairwell in the collapsed northeastern tower once provided access to an intramural passage at first-floor level.

The castle’s sophisticated design reveals the engineering prowess of its medieval builders; the ground floor features a barrel vault, with the surviving northern wall cleverly stepped inward above it to support the first floor independently. Four internal rounded openings in the north wall narrow to simple rectangular windows on the exterior, and remnants of a wall-walk with drainage holes and decorative string course crown the top of the wall. The entire structure sits at the eastern end of a rectangular ditched enclosure, approximately 52 metres by 18 metres internally, surrounded by a four-metre-wide fosse that extends westward before turning south to meet the current field boundary.

Archaeological excavations in 2001 and 2006 have revealed the castle’s long and varied occupation history, uncovering metalled surfaces, post-holes, and hearths dating from the fourteenth century through to the eighteenth century, when brick ovens were constructed on site. The investigations also discovered that whilst the south and west walls had collapsed at some point, they were faithfully rebuilt along their original lines during the nineteenth century using drystone construction techniques, incorporating fragments of the fallen barrel vault that still bore traces of their original wicker centring. Despite extensive plundering over the centuries, with many facing stones removed for use elsewhere, Kindlestown Castle remains a compelling testament to medieval Irish fortification and domestic architecture.