In Benderloch at the south end of Tralee beach that runs out from the Castle, a grassy hillock bears on its top the faint trace of Dun Mhic Uisneachan, the fort of the sons of Uisneach.
Some historians consider the fort to have been Beregonium, the seat of Pictish kings, and it was so named by George Buchanan (sixteenth century) in his Latin History of Scotland.
Support is given to this notion by the local tradition that Pictish kings were buried on the island of Lismore, which lies only one and a half miles off the coast.
Beregonium, like the Scots fort on Dunadd, was a multiple structure incorporating several forts on the one hill.
The earliest recorded occupation of the current site dates back to that of a "St Columba" cell around the 6th Century. Parts of this are still visible in the undercroft of the "Chapel" and under the main part of the Castle.
The next building period is 15th Century, the vernacular building to rear of the Castle, now known as the "Chapel", following which the neoclassical front of the building was erected in 1730; finally this and the Chapel were joined together in 1780 by the modern and now mostly ruined Georgian Castle.
The estate as it stands today is only one part of the property amassed by the Campbell's of Lochnell, a branch of the Campbell line of the current Duke of Argyll, and the same family that raised the foot regiment that became the Argyll and Sutherland Highlanders.
The Campbell family sold the estate in 1912 to the head of the Cochrane family, who's descendant broke up and sold the estate in 1949, following it's requisition as a brigade headquarters during World War II.
The principal part of the estate went through multiple ownership before being repurchased in 1962, by the the then head of the Cochrane family.