This impressive defensive structure consists of a flat-topped circular mound, roughly 17.5 metres across at its summit and rising between 7 and 14 metres high depending on which side you approach from. The base spreads out to approximately 40 metres in diameter, creating the steep-sided profile typical of these Norman fortifications. Attached to the northwest side lies a rectangular bailey, a fortified courtyard measuring about 40 metres square, which would have contained the everyday buildings of the castle complex. The bailey’s boundaries are still clearly visible as earthen banks and scarps, with the northwestern bank reaching 15 metres wide at its base.

The site’s history stretches back to at least the early 13th century, when the area was known as Killamlan. According to historical records from 1214-15, William de Tuite reportedly discovered gold here, adding an intriguing dimension to the location’s medieval significance. The motte wasn’t an isolated fortification; it formed part of a larger medieval landscape that included a field system immediately to the northwest, evidence of the agricultural economy that supported the castle’s inhabitants. Just north of the bailey are the remains of another castle site, whilst Killallon parish church stands about 90 metres to the northeast, creating a cluster of medieval structures that speak to the area’s former importance as a local centre of power and administration.

Today, the grass-covered mound and its associated earthworks offer visitors a tangible connection to Ireland’s Anglo-Norman past. The varying heights of the motte, from 7 metres on the northwestern side to 14 metres on the southeastern side, suggest it was built to take advantage of the natural topography, maximising its defensive capabilities whilst minimising the earthmoving required during construction. These surviving earthworks represent one of the many motte and bailey castles that once dotted the Irish landscape, serving as both military strongholds and administrative centres for the new Norman lords who arrived in Ireland during the 12th and 13th centuries.