Coordinates: 53°19′30″N 6°19′58″W / 53.324973°N 6.332840°W
Drimnagh Castle (Irish: Caisleán Dhroimeanaigh) is a Norman castle located in Drimnagh, a suburb of Dublin, Ireland. It is the only remaining castle in Ireland with a flooded moat around it; this moat is fed by a small local river, the Bluebell. Drimnagh Castle Christian Brothers Schools is located next to the site of the castle.
The earliest recorded owner of Drimnagh Castle was Sir Hugh de Bernival (his name is recorded in state papers relating to Ireland in 1216). His family, owners of Drimnagh Castle for centuries, were later known as Barnewell, sometimes Barnewall. The last occupants of Drimnagh Castle were the Hatch family.
In the very early 1900s, the castle and its lands were bought by Joseph Hatch (born 1851), a dairy man, of 6 Lower Leeson Street. Joe Hatch was a member of Dublin City Council, representing Fitzwilliam Ward, from 1895 to 1907. He bought the castle in the first instance to provide grazing land for his cattle. He restored the castle, which became a summer home for his family and a splendid location for the celebration of the silver wedding anniversary of Joseph Hatch and his wife, Mary Connell, as well as the marriage of their eldest daughter, Mary, in 1910.
Upon his death in April 1918, ownership of the castle passed to their eldest son, Joseph Aloysius (born 1882), known as Louis. Together with his brother Hugh, Louis managed the dairy farm and the dairy shop in Lower Leeson Street. Louis (who never married) died in December 1951. (Hugh, who did not marry until the age of 60 in 1944) died in 1950.
Drimnagh Castle was left by Louis Hatch to Dr. P. Dunne, Bishop of Nara (‘Castle Bequest to Bishop’, The Irish Times, 9 January 1953), who sold it (reportedly for a nominal sum) to the Christian Brothers to build the school that now stands there.