Built into the hillside with commanding views sweeping from the north-northwest to the south-east, this limestone structure tells a complex story of religious change and architectural adaptation. According to the historian Carrigan, writing in 1905, the original parish church dedicated to St Catherine was demolished around 1700, when a Protestant church was constructed on its foundations. The tower, which had been attached to the western end of the medieval church, was preserved and incorporated into the new building scheme, with a late 17th or 18th-century church built directly onto its eastern wall.

The tower itself is a substantial structure, constructed from roughly coursed limestone rubble with walls measuring 1.5 metres thick and featuring well-cut corner stones at the northwest and southwest angles. Though much of the western wall has collapsed and only the first floor level remains intact, the surviving architecture reveals fascinating defensive and domestic details. The main entrance from the church was cleverly defended by a murder-hole concealed in the wall thickness above the doorway, whilst inside, a spiral staircase winds upward through the southeast corner, illuminated by two narrow loops. A particularly intriguing feature is the large wall cupboard built into the eastern wall; accessed through a flat-headed opening about 0.9 metres above floor level, this commodious storage space measures nearly two metres high and over a metre deep.

The ground floor consists of two vaulted chambers connected by a pointed doorway through a dividing wall that measures 1.4 metres thick. The southern chamber, measuring 3.8 by 2.5 metres, features a pointed vault with traces of the original wicker-centring still visible, lit by a flat-headed window in the south wall. Below the vault, a loft space was illuminated by a loop window, whilst two massive corbels project from the western ends of the north and south walls. The northern chamber, slightly larger at 4.4 by 2.6 metres, has suffered more damage over time with its pointed vault partially collapsed, though a series of joist-holes in the eastern wall indicates that this room also once contained a loft space just beneath the vault.