The rectangular enclosure measures approximately 36 metres from northeast to southwest and 28 metres from northwest to southeast, creating a substantial protected area that would have once housed a farmstead or small manor. The site’s defining features include an impressive earthen bank system with varying heights; the inner bank reaches 0.9 metres on the interior side and rises to 1.7 metres on the exterior, whilst the accompanying moat stretches up to 9 metres wide at its top, narrowing to 6.7 metres at its base with a depth of 1.5 metres.

The defensive earthworks show remarkable variation around the perimeter, suggesting different phases of construction or adaptation to the local topography. Along the southeastern edge, the inner bank stands 0.6 metres high on the interior, increasing to 1.6 metres externally, with its moat measuring 8 metres wide at the top and tapering to 6 metres at the base, though notably shallower at just 0.8 metres deep. An outer bank, ranging from 0.5 to 1.5 metres in height and approximately 2 metres wide, provides an additional layer of defence on the northeastern and southeastern sides. The southwestern and northwestern boundaries tell a different story; here, an abandoned laneway, roughly 3.5 to 4 metres wide, suggests the site’s integration with local transport routes and its eventual decline.

Today, the site lies overgrown, its once-formidable defences softened by centuries of weather and vegetation. Modern agricultural needs have left their mark too; drainage cuts on either side of the northeastern moat have created a raised central area, altering the original medieval waterworks. These moated sites, common throughout the Irish countryside, served as fortified farmsteads during the Anglo-Norman period and later centuries, providing security for agricultural communities whilst demonstrating their owners’ status and resources. This particular example at Harristown Big, documented in the Archaeological Inventory of County Wexford and updated by researcher Michael Moore in 2012, stands as a well-preserved reminder of how medieval communities balanced the practical needs of farming with the ever-present requirement for defence.