The Ordnance Survey 25-inch map recorded it as a roofed rectangular building, roughly 12 metres long running east-northeast to west-southwest, and about 6 metres wide. It sat along the southern edge of a laneway that connected to the river, marking what was likely once a more substantial medieval site.

By 1984, both the laneway and any visible traces of the castle had vanished from the landscape. Agricultural work had taken its toll on the site, leaving it preserved only in historical records and maps. The building’s rectangular footprint and its designation as a ‘castle’ on OS maps suggest it may have been a tower house or fortified dwelling, though without archaeological investigation, its exact nature remains uncertain.

Today, the site exists primarily as a record in the Sites and Monuments Record (SMR) files, compiled by Gearóid Conroy in 2012. Like many of Ireland’s lost medieval sites, this Walshestown castle serves as a reminder of how quickly even substantial stone structures can disappear from the landscape through a combination of agricultural activity, stone robbing, and the passage of time. Its location near the Liffey would have been strategically advantageous, controlling river crossings and providing access to water; a common pattern for medieval fortifications throughout County Kildare.