The site is enclosed by limestone rubble walls, now largely ruined and cloaked in ivy, which follow the natural defensive line of the cliff on the northern and eastern sides. Today, the interior is mostly filled with overgrown heaps of rubble, though careful examination reveals traces of what were likely defensive towers at the northwest angle and on the southern side.

The southern structure preserves the most substantial remains, including a southwest wall that stands up to 4 metres high and features an external base batter; a defensive architectural feature that provided additional stability and made the walls harder to scale. This wall contains a splayed gun loop, indicating the castle’s adaptation to gunpowder warfare. The structure at the northwest angle is built precariously along the cliff edge, with its north wall constructed about 2 metres below the main site level. Near its western end, a garderobe chute exits directly over the cliff, providing a rather vertiginous medieval toilet arrangement, whilst traces of what may have been additional gun loops can be seen in the surviving masonry.

The castle has a turbulent history dating to at least 1317, when Milo fitzPhilip de la Roche was pardoned for burning the Condon manor here. The Roche family subsequently acquired Carrigdownane during the 14th century and held it for generations. The Down Survey maps of 1655;6 show both the castle and a mill immediately to the southeast, suggesting the site remained an active centre of local power and economy well into the early modern period. Today, these ivy;wrapped ruins offer a tangible connection to centuries of conflict, defence, and daily life on this strategic clifftop position.