The time line for buildings at Ardkinglas is not straight forward.
On a stony ridge on Rubha Mor is what is recorded as a well. There now appears to be evidence of it being an “early place” or defensive building.
The Royal Commission for Historical and Ancient Monuments of Scotland (RCHAMS) quotes the report of 1792 by Rev. Dugal McDougals for the First Statistical Account “of three separate towers and stout walls about 15 feet high. In the course of this wall is the great gate, which is defended by small round turrets in flank, with apertures, through which those who assailed the gate might be annoyed with arrows or with small firearms. A small tower immediately above it, the gate-tower, also defended the gate. The courtyard measured 98 feet in each direction and within the walls were smaller buildings for lodging servants, for holding arms and for storehouses and cellars.” However the same report mentions “the old residence of the family of Ardkinglas of which the ruins can now scarcely be traced, was at a small distance from the present castle but in a more commanding position.” Perhaps this is the “well” mentioned above.
Ardkinglas was the seat of an important branch of the Campbell family descended from Colin (Caileen Oig), son of Colin Campbell of Lochawe, who probably received the extensive estate, lying between Loch Fyne and Loch Long, at about the time of his marriage in 1396. It was chosen when “in obedience to a predicted omen his hamper strings should snap”. Sir Colin granted it “in all its righteous heaths and marches or as long as woods shall grow and water flow”. The feudal condition attached was the provision by the new family at their own expense of two war galleys, one of eight oars and the other of six, to serve the Lord of Lochawe or the King of Scotland in times of war and tumult.
On 21st July 1563 Mary Queen of Scots is reported to have stayed at Ardkinglas on her way from Carrick to Inveraray. In 1586 there is a note of repairs to a castle as Ardkinglas. Pont’s map circa 1580 seems to show two castles. One hundred and sixty years later Sir James Callander born in 1744 states in his memoir
“At the time of my birth, my father and mother were on a visit to my great grandfather, Sir James Campbell, at his baronial seat of Ardkinglas on the banks of Loch Fine. It was a fine old mansion, built in the form of a quadrangle, with a considerable court-yard in the centre. At each corner was a tower of sufficient dimensions to make it the residence of some cadet of the family. I have often regretted that the late Sir Alexander Campbell should have thought of demolishing this noble pile, for the purpose of raising in its stead a great square of masonry..”
The castle was reported destroyed in 1769. There is no evidence of when the original castle was abandoned or when the second one was occupied. Perhaps the first was just a place of defence and was never a residence. 
During the 18th century there had been several plans to build a country house at Ardkinglas and some famous architects were commissioned to produce designs. Among these were Colen Campbell (1676 – 1729) , Robert Adam (1728 – 1792) and later James Playfair (1755 – 1794). In Playfair’s plan of 1790 he writes that “the castle be left in part as a ruin (to) be a gardener’s house and hovel for cattle”. A house was built in 1795 and was described as a classical house of two storeys above a basement.
The mansion was nearly derelict in 1822 when Dorothy Wordsworth wandered through the estate and it was completely destroyed in 1831, ''destroyed by a fire a few years ago, as the tradesmen were just finishing repairs it had undergone....'' (Rev John McDougal 2nd Statistical Account) The nearby stable block was converted to serve as the main house.
Nearly half of this house was taken down when the current house was built in 1907 and the rest converted to workshops. The first floor and roof of the 'Old House' were demolished in October 1966. The fire panel in the drawing room in Lorimer's House came from this house and is the only thing known to have been transferred.
