Castle Magner lies in the townland of Castlemagner, north west of the town of Mallow, in County Cork in Ireland.
The first fortification in this area was a Norman motte and bailey, built around 1183 by a Norman settler by the name of William Magner, brought here by Philip de Barry. In 1200 a Norman tower was built on a hill at this site, overlooking a holy well.
In 1375 a watchtower was built adjacent to the Norman tower, which was converted to a granary. It was quartered and maintained by the Magner family. During the Gaelic rebellion of 1460 the watchtower was destroyed. In 1467 the Norman tower, which had remained unharmed, was rebuilt and turned into a castle. Amongst other things an enclosed spiral staircase was added.
During the rebellion of 1598-99, Castle Magner was destroyed except for the enclosed spiral staircase. It is that towering staircase that we still see today.
The stair turret stands in a fragmentary bawn, now an abandoned farmyard since 1971. There are also the remains of an 18th century house next to it. A nice and atmospheric location. Access is prohibited.