Stretching approximately 170 metres from north to south and 160 metres east to west, this impressive defensive structure would have been a formidable sight in its heyday. Today, what remains is a low earthen bank, roughly three metres wide and standing less than a metre high on the inside, though it rises to over two metres on the exterior slope. The bank is now thoroughly overgrown with briars and thorns along its northern section, making it difficult to fully appreciate its original scale.

The bawn’s defensive capabilities were enhanced by an outer fosse, or ditch, measuring just over two metres wide and originally dug to a depth of about 1.2 metres. This ditch has since been repurposed as a modern field drain, a common fate for many historical earthworks across the Irish countryside. The eastern side of the enclosure, which would have bordered the tower house, has been completely removed and now lies beneath a farm track, severing the physical connection between these two defensive structures that once worked in tandem.

The interior of this hexagonal enclosure is remarkably level and featureless today, offering few clues about how the space was once utilised. Given its substantial size and proximity to the tower house, it likely served multiple purposes; providing a secure area for cattle during raids, temporary accommodation for tenants seeking protection, and perhaps storage for valuable goods. Despite its poor preservation, the sheer scale of this bawn hints at the importance of the Blackwood tower house and the resources its owners once commanded in medieval Kildare.