The site consists of a stone and earthen bank, now standing about half a metre high, with a single gap in the northeast sector that likely served as the original entrance. Within this ancient enclosure, visitors can spot a semicircular hollow in the southeast quadrant; measuring 2.5 metres wide and 0.8 metres deep, it may have been repurposed as a lime kiln in more recent centuries.

Near the centre of Rathnacross lies an intriguing oval pit, roughly 2 metres by 1.25 metres and 0.6 metres deep. This depression probably marks where a standing stone once stood, as recorded on the first edition Ordnance Survey maps from the 19th century. Local tradition holds that this missing stone was actually a termon cross, a boundary marker that gave Rathnacross its name; ‘rath na croise’ translates to ‘fort of the cross’. The site’s position along an old route to Lough Derg, one of Ireland’s most important pilgrimage destinations, adds weight to this religious interpretation.

Archaeological surveys suggest this ringfort, or rath, dates back to the early medieval period when such structures dotted the Irish landscape as defended farmsteads for prosperous families. The nearby Drumawark area contains similar earthworks, indicating this region of Donegal was well settled during this era. Though the standing stone has vanished and time has softened the earthen banks, Rathnacross remains a tangible link to Ireland’s medieval past, when pilgrims may have paused here on their journey to seek penance at the sacred waters of Lough Derg.