Carnell consists of a 15th century stone keep to which has been attached a 19th century mansion house.
The lands of Carnell were owned by the Wallace family as far back as the mid-15th century, with Adam Wallace being the first described as of Carnell. At some point in the 15th century the tower was built, and measures around 12 metres in height.
In the 16th century a new house was built to the east by the Wallace family, including a spiral stair tower and a caphouse. A carved stone within the old tower carries the date 1576 and a pair of initials, and probably came from the newer building.
In 1812, following the deaths of her four brothers, Carnell (by now known as Cairnhill) passed to Lillian Wallace, who had married Walter Ferrier of Somerford in 1784. They had five daughters and four sons, the eldest of whom, Colonel John Ferrier, inherited Cairnhill. He also inherited, from his uncle William Ferrier Hamilton, the estates of Westport and Cathlaw in West Lothian, and took the name Ferrier Hamilton.
Colonel Ferrier Hamilton commissioned William Burn, in whose office David Bryce was working, in 1843 to build extensive additions at Cairnhill, which filled in the space between the two older buildings, and created a grand new south facade. Further additions by Wardrop & Reid followed in 1880.
In 1904 Georgina Findlay-Hamilton, a granddaughter of Colonel Ferrier Hamilton, inherited the estate from a cousin, and commissioned alterations to the house, as well as doing considerable work in the grounds to lay out the ornamental gardens. Her son-in-law and daughter, Commander and Mrs JB Findlay, took over the estate and continued to develop the gardens until 1965, when it was transferred to their son John Findlay, and in turn to his son Michael Findlay.
As well as being a family home, Carnell is now run as an exclusive venue and luxury accommodation, and in 2011 played host to Brad Pitt and Angelina Jolie while Pitt was filming World War Z in Glasgow.