According to antiquarian P.C. Lyons, writing in 1934, a castle once stood on a knoll about 300 yards north of Redmonstown House, possibly belonging to the Le Poer family. He described the remains as two parallel banks of rubble, measuring 25 feet long and 15 feet apart, marking where the castle had stood in the northeast corner of a bailey that covered roughly an acre.

Today, visitors searching for these medieval remnants will find little trace of what Lyons documented. The original Redmonstown House has been demolished and replaced with a modern bungalow, and the surrounding landscape has been thoroughly altered. Previous landowners levelled the fields around the house, erasing the knoll that once held the castle. The land now slopes gently towards the river, with only a stone wall of roughly coursed limestone running northwest to the riverbank; no cut stone from the castle appears to have been incorporated into its construction.

The exact location of Redmondstown Castle remains uncertain, with the current site marker serving only as a general indication of where Lyons believed it once stood. Like many of Ireland's lost castles, Redmondstown exists primarily as a tantalising entry in historical surveys, a reminder of the medieval landscape that once dominated this part of Tipperary. The Le Poers, if they were indeed the castle's owners, left no other trace of their presence here, and the fortress that once guarded this stretch of the Anner has been completely reclaimed by time and agricultural progress.