In 1403, King Robert III granted the lands of Ardgowan to his natural son, Sir John Stewart.
Ardgowan castle, now a ruin, is a tower house built within the site of the earlier castle, and is dated to the late 15th century.
It is sited on the south edge of the promontory, perched on a cliff.

In 1667 Archibald Stewart was created a baronet.
The 3rd baronet married, in 1730, Helen Houston, heiress of the Shaws of Greenock.
Their son Sir John Shaw Stewart, 4th Baronet, commissioned a design for Ardgowan House from the architect Hugh Cairncross.
Construction began in 1797, and was completed around 1801, after which the old castle was abandoned.
Its ruin was consolidated and repaired in 1936.
In 1403, King Robert III granted the lands of Ardgowan to his natural son, Sir John Stewart. Ardgowan castle, now a ruin, is a tower house built within the site of the earlier castle, and is dated to the late 15th century. It is sited on the south edge of the promontory, perched on a cliff.
In 1667 Archibald Stewart was created a baronet. The 3rd baronet married, in 1730, Helen Houston, heiress of the Shaws of Greenock. Their son Sir John Shaw Stewart, 4th Baronet, commissioned a design for Ardgowan House from the architect Hugh Cairncross. Construction began in 1797, and was completed around 1801, after which the old castle was abandoned. Its ruin was consolidated and repaired in 1936.
Ardgowan Castle