To the south and east, the Slieveardagh hills dominate the landscape, providing a dramatic backdrop to this much modified medieval stronghold. Built around 1306 by John Butler, son of Edmund Butler, the first Earl of Carrick, the castle began life as a late 13th or early 14th century keep constructed from limestone rubble with roughly coursed masonry and crude quoins.

The original rectangular keep measures approximately 18.74 metres northeast to southwest and 10.7 metres northwest to southeast, with walls nearly two metres thick. A stair turret projects from the northwest wall, appearing to have been built against the existing structure rather than integrated into the original design; whilst the lower courses simply abut the rectangular block, the upper sections are keyed in, suggesting this may have been a deliberate construction technique rather than evidence of separate building phases. The tower house underwent significant modifications in the late 16th or early 17th century, when mullioned windows and fireplaces were inserted to bring the fortress more in line with contemporary domestic comforts. A gabled extension topped with a chimney stack was added to the west end of the northwest wall, whilst a circular bartizan was constructed at the western angle, though only its lower northern side and supporting corbels survive today.

By the time of the Civil Survey of 1654 to 1656, the property belonged to Pierce, Lord Viscount Ikerrin, described as an 'Irish Papist', with the survey noting it as 'a good castle, a slate house with a large bawne'. The building southwest of the stair turret contains three storeys with an attic space, whilst the northeastern section manages to squeeze four storeys into the same height, demonstrating the medieval builders' efficient use of vertical space. The original curtain wall of the keep continued to serve as a bawn, or fortified courtyard wall, even after the Tudor period renovations transformed it into a fortified house more suited to the changing needs of its aristocratic inhabitants.