The castle itself has long since vanished; when antiquarians surveyed the spot in 1840, they found only a few foundation stones on the north side of the summit, and even those traces are no longer visible today. According to records from Ulster’s Office, the White family supposedly built the castle here in 1418, though this claim is dubious given that the family name appears in local records from before 1200. The castle changed hands numerous times throughout the 16th and 17th centuries, passing between various branches of the O’Brien clan, before being granted to Edward Fytton in 1587 and later purchased by Edward Cosgrave of Dublin in 1703.

The site owes its modern fame not to the vanished castle but to the dramatic events of August 1690, when Patrick Sarsfield, a cavalry commander in James II’s Irish army, used the rock as a vantage point for one of the most audacious raids of the Williamite War. Following the defeat at the Battle of the Boyne, the Irish forces had regrouped at Limerick, where William of Orange laid siege in August. When Sarsfield learned that heavy siege guns were en route from Dublin to break the city’s defences, he led 600 cavalry on a daring nighttime raid, destroying the entire Williamite siege train in the fields below this very rock on the night of 11th to 12th August. The success of this mission helped the Irish hold Limerick for another year, ultimately leading to the Treaty of Limerick in 1691.

Today, the summit serves as a viewing point complete with metal railings and a flagpole, where visitors can look down on the site of the former English camp where Sarsfield’s raid took place. Several plaques commemorate the site’s history in both Irish and English, including a map showing the route Sarsfield’s cavalry took from Limerick. Though the castle that once crowned this rock has been reduced to memory, the site remains a tangible connection to one of the most celebrated episodes of Irish resistance during the Williamite War; a moment when 600 horsemen changed the course of a siege and earned their commander a place in Irish folklore.