Though only the north wall and partial returns of the east and west walls survive today, this rectangular tower house once soared at least five storeys high. The entire structure is now romantically clad in ivy, but careful examination reveals fascinating defensive features, including a distinctive triangular spur projecting from the northeast corner; a rare architectural element shared with only a few other Irish castles like Mashanaglass and Carrignacurra.

The castle's original entrance was through a ground floor doorway near the north end of the east wall, leading into a lobby that connected to a small vaulted guardroom. The defensive sophistication is evident in the gun loops strategically positioned to cover the entrance, and the later addition of the triangular spur, which contained its own vaulted chamber complete with fireplace at first floor level. The tower originally featured vaults over the first and third floors, though only their springings remain visible along the north wall. A damaged fireplace on the second floor and various blocked or modified openings hint at the castle's evolution through centuries of occupation and conflict.

Originally known as Carriganeide and built by the Condon family, the castle passed through several hands before being leased to John Meaghe in 1587. A contemporary description paints a vivid picture of its formidable defences, noting it was "strongly built upon the river Broadwater", with four storeys of double vaulting, and remarkably, an iron door "double chained and strong for defence", likely referring to a yett, though no evidence of this defensive gate survives. The castle was granted to Arthur Hyde in 1588, from whom it takes its present name, and later the Hyde family built Castle Hyde country house approximately 50 metres to the southeast, leaving the medieval tower to gradually succumb to the elements.