The site's military past is documented in the Down Survey barony map from 1658-9, which depicts a large square enclosure straddling the border between Cahersherkin and Lisroe townlands, labelled simply as 'a bawne mount'. A bawn was typically a fortified enclosure built to protect livestock and inhabitants during the turbulent centuries of Irish history, particularly during the plantation period.

The house that now occupies this spot has carried the name 'Fort House' through successive Ordnance Survey maps, appearing on both the 1840 and 1916 six-inch editions. This naming convention suggests a long-standing local awareness of the site's defensive origins, even as the physical evidence disappeared beneath later construction. When archaeologists Mary Tunney and Lynda McCormack surveyed the location in 1999, they found no visible remains of the original fortification above ground, though the property owner confirmed that local tradition held the house was built directly on top of the old fort.

This pattern of domestic buildings rising from the foundations of earlier defensive structures is common throughout Ireland, where centuries of conflict gave way to more peaceful times and fortified sites were repurposed for everyday living. While the bawn mount at Lisroe has vanished from view, its memory persists in both cartographic records and the very name of the house that replaced it, offering a glimpse into how the Irish landscape has been continuously inhabited and reimagined across the centuries.