The site’s history stretches back to the late 12th century when it served as a preceptory for the Knights Templar, who likely received the land through Henry II’s 1172 grant of the church of St. Alloch. The name Kilcloggan itself derives from Cill Eallóg, meaning Alloch’s church, after a saint who was said to be the son of Díona, daughter of a Saxon king, and Brachan, a Welsh king. When Pope Clement V suppressed the Templars in 1312, their property transferred to the Knights Hospitaller of St. John of Jerusalem, who built the current castle as the centre of their manor estate.

The Hospitallers managed a substantial agricultural operation here until their own suppression in 1541, with the demesne comprising 120 acres alongside the castle, whilst various tenants worked additional lands totalling nearly 500 acres. A detailed 1307 inventory of Templar chattels survived the centuries, though frustratingly it omits descriptions of the buildings themselves. Following the dissolution, the property changed hands several times before Sir Dudley Loftus acquired it in 1596, and his family retained ownership well into the late 19th century.

The castle itself is a compact rectangular tower measuring roughly 6 metres by 5.7 metres, built from Old Red Sandstone conglomerate with projecting towers at the north and west corners housing stairs and garderobes respectively. Rising 17 metres to the wall-walk, it contains four floors accessed by mural and newel stairs, each level featuring period details like ogee-headed windows, fireplaces, and window seats. The ground floor retains its barrel vault with traces of wicker-centring still visible, whilst the upper floors showcase the domestic arrangements of a late medieval fortified residence. Most impressively, the stepped crenellations on the roof remain perfectly preserved, complete with lookout platforms at the corners, offering visitors a rare glimpse of intact medieval defensive architecture. A fragment of the original bawn wall extends from the north corner, including the jamb of a gateway with bar-holes that once secured the entrance to this formidable stronghold.