[2][3] Today, all that remains of the castle is a tower, perched on the edge of a plateau, looking down on a flat tract of land between it and the shore of the Firth of Clyde.

Archibald MacAulay, 9th laird (died 1752), began the process around 1700,[9] and the sales continued under his sons - one of whom wrote a primer on shorthand in an effort to raise money.

[10] By the time the 12th laird died around 1767, the roof had fallen in and the overall condition of the castle had deteriorated to such an extent that he had been forced to abandon his residence there and live in nearby Laggarie, having completed the sale of the MacAulay estates.

It was during the Campbell's tenure as lairds of Ardencaple in the 18th century that extensive development was done on the estate by Robert Adam - Scotland's foremost architect of the time.

In 1764, while the house was in possession of Lord Frederick Campbell, Robert Adam was first consulted about work on the castle.

However, nothing came of this scheme and it wasn't until 1774 that Adam came up with a set of drawings for an addition to the southern half of the west front of the house.

Later photographs of Ardincaple Castle show that Adam's extension had been altered or that some features present in his sketch were omitted from being implemented.