This moated site, marked as ‘Fort’ on Ordnance Survey maps from 1836 and 1876, consists of a raised rectangular platform measuring approximately 45 metres north to south and 25 metres east to west. The site’s defensive architecture follows a classic medieval pattern: an inner earthen bank enclosing the raised area, a wide and deep fosse (or defensive ditch), and traces of an outer bank that once provided an additional layer of protection.

The fortification’s preservation varies around its perimeter, telling a story of both resilience and gradual decay. Whilst the inner bank remains well-preserved on most sides, the eastern section notably lacks both the outer bank and fosse, suggesting either an original design choice or later modification. The outer bank has been levelled at the north-northwest corner, though its outline remains clearly traceable in the earth, like a ghost of the site’s former defences. A break in the northern banks, complete with an accompanying causeway across the fosse, likely marks the original entrance where medieval inhabitants would have crossed into the protected enclosure.

These moated sites, common throughout medieval Ireland, served as fortified homesteads for Anglo-Norman settlers and Gaelicised families from the 13th century onwards. The substantial earthworks at Swellan Lower would have supported timber palisades and buildings within the enclosed area, creating a defendable residence that balanced domestic comfort with military pragmatism. Today, this grass-covered monument stands as a tangible link to Cavan’s medieval past; its banks and ditches preserved as subtle undulations in the modern landscape.