The site sits amongst a cluster of historic monuments; a chapel and graveyard lie 230 metres to the north-northeast, a motte and bailey castle stands 240 metres to the east, and Castle Kindalen can be found 250 metres to the northwest. According to Thomas O'Conor's Ordnance Survey Letters of 1837, local tradition held that this was the castle from which the townland took its name, rather than the nearby Castle Kindalen, suggesting this was the primary MacGeoghegan stronghold in the area.

Historical records paint a picture of the castle's significance to the MacGeoghegan family. In 1624, an inquisition following the death of Hugh Geoghegan recorded that his Castletown Kindalen manor included one castle and a watermill, which passed to his son Arthur. The Down Survey map of 1654-56 depicts the medieval castle as a tower house standing beside St Mary's Church of Vastina, home to Art McHugh Geoghegan in 1641. Art, described as an 'Irish papist' and son of Hugh, owned 395 acres in the townland at that time.

Today, the site presents as an irregular D-shaped area marked by low scarps and field banks. An Archaeological Survey of Ireland visit in 1979 found the remains challenging to interpret; the straight northeastern side is formed by a field fence with hedging on a low bank, whilst a scarp curves around the western and southern edges. The interior slopes unevenly and shows traces of old cultivation ridges running east to west, with a low rectangular earth platform in the southern corner occupying the highest point of the site. Though its original form remains somewhat unclear, the site continues to offer tantalising evidence of the MacGeoghegan family's medieval presence in this part of Westmeath.