Grennan Castle, Thomastown, Kilkenny

Grennan/Grenan Castle

Anglo-Norman Castle

Grennan castle was built in the 13th century by the Anglo-Norman, Thomas FitzAnthony. Shortly after arriving in Ireland with William Marshall he became Seneschal of Leinster. The townland is still known by the name FitzAnthony gave to the area of land around the castle, Grennan. Thomastown, the village that built up around the manor house, was named after him. He was the founder of St Mary's parish church in Thomastown and the Priory of Inistioge. As FitzAnthony's only son predeceased him his estate was divided amongst his five daughters.

The twenty metre long rectangular castle stands on the west bank of the River Nore. The ruin was in relatively good condition up until the early 19th century, since then the courtyard walls and outer buildings have been destroyed. These included a water mill, outhouses and large orchards. Originally the three chambered, each barrel vaulted, ground floor was divided into two storeys. On the next level was the 15 metre long great hall. The storey above the hall was supported on corbels. Sadly all the windows, doors and most of the quoin stones have been robbed from the structure. There is a new walking trail from Thomastown to Inistioge that passes right by the ruin.

Situated: From Thomastown head south on the R448, 200 metres after crossing the river, turn left onto the Mall. After 200 metres turn left onto Castle Ave.

Discovery Map 67: S 5923 4143. Last visit July 2017.

Longitude: 7° 7' 38" W

Latitude: 52° 31' 16" N

Google Map

Photos: Jim Dempsey.

Grennan/Grenan Castle Anglo-Norman Castle Grennan castle was built in the 13th century by the Anglo-Norman, Thomas FitzAnthony. Shortly after arriving in Ireland with William Marshall he became Seneschal of Leinster. The townland is still known by the name FitzAnthony gave to the area of land around the castle, Grennan. Thomastown, the village that built up around the manor house, was named after him. He was the founder of St Mary's parish church in Thomastown and the Priory of Inistioge. As FitzAnthony's only son predeceased him his estate was divided amongst his five daughters.
The twenty metre long rectangular castle stands on the west bank of the River Nore. The ruin was in relatively good condition up until the early 19th century, since then the courtyard walls and outer buildings have been destroyed. These included a water mill, outhouses and large orchards. Originally the three chambered, each barrel vaulted, ground floor was divided into two storeys. On the next level was the 15 metre long great hall. The storey above the hall was supported on corbels. Sadly all the windows, doors and most of the quoin stones have been robbed from the structure. There is a new walking trail from Thomastown to Inistioge that passes right by the ruin.

Situated: From Thomastown head south on the R448, 200 metres after crossing the river, turn left onto the Mall. After 200 metres turn left onto Castle Ave. Discovery Map 67: S 5923 4143. Last visit July 2017. Longitude: 7° 7' 38" W Latitude: 52° 31' 16" N Google Map Photos: Jim Dempsey.