Situated at the western extremity of Cork Harbour, in the Barony of Kerricurrihy, is the now ruined castle of Monkstown. The name is derived from the Monastery Legan, belonging to the Benedictine Monks, which was formerly established here, it being a cell of Bath Abbey.

The castle consists of a quadrangular building, flanked by four square towers, having machicolated defences projecting from their angles. The windows are in excellent preservation, being of square Tudor style, divided by strong stone mullions, with horizontal weather cornices. The moulding of the door displays excellent workmanship.

The estate belonged to the Archdeacons, who changed their name to MacOdo, or Cody.

The castle was erected in 1636 by Anastasia Archdeacon, nee Gould, who intended it as a pleasant surprise for her husband, who was a naval officer, and away on a voyage at the time.

Tradition says that it only cost the thrifty lady a groat. At first she found that the builders objected to go to so out-of-the-way a situation, as provisions were difficult to procure. Nothing daunted by such an excuse the lady offered to supply the workmen with provisions at the ordinary retail rate. This she did, but as she purchased her goods at wholesale prices she found when she came to balance her accounts that she was only 4d. out of pocket.

The castle was erected in a twelvemonth and a day, and the date 1636 appears on one of the mantelpieces.

Smith states that the fortress was originally styled Castle Mahon or O’Mahony’s Castle, and in an ancient MS. document (probably now in the possession of Captain Shaw, late of the London Fire Brigade) it is described as being “remade” at the above date, so that it may occupy the site of an older stronghold.

The following interesting extracts are taken from the manuscript alluded to, which has been preserved in the Shaw family, they having at one time leased the castle: “A.D. 1636, Monkstown Castle and court were remade. Reader, you are to observe that it was not John Archdeacon, but his wife, Anastatia Gould, who built the four castles of Monkstown, and the court, in his absence, as he was from home. On his return he did not like the building, and said that a building near a harbour was a building of sedition, which, alas! turned out so.”

“A.D. 1660.—Archdeacon died, as when Cromwell came to Ireland he was deprived of his castle, lands, &c., but not his life, which they did not covet.”

In 1612 the wardship of the son of the late John Archdeacon, of Monkstown, was given to Sir John Jephson Knt., and it was this ward’s wife who afterwards built the castle.

He died in 1660, and both he and his wife are buried in the disused graveyard of Teampul Oen Bryn, west of the castle. Upon his tomb appears a long Latin inscription which, among other things, states that—“Here lies the body of that most noble man, John Archdeacon.”

Colonel Hunks, one of the three deputed to execute the death warrant of Charles I., was granted the lands of Monkstown by the Commonwealth before the demise of John Archdeacon, who lost his estate on account of loyalty to the Stewarts. Hunks sold it to Primate Boyle, brother of the Earl of Cork, for £400.

But it evidently returned to the Archdeacon family upon the Restoration, for it was again confiscated in 1688 on account of the family’s loyalty to King James.

It then passed again into the hands of the Boyles, and through two granddaughters of the Primate it descended to the present owners, the Lords De Vesci and Longford.

In 1700 Dive Downes writes: “Mr. O’Callaghan, a Protestant, lives in Monkstown, in a good square castle with flankers.”

Later in this century it was rented by the Government as a barrack.

Lord De Vesci leased the castle to Bernard Shaw in 1861.