The Ballantines of Ayr were said to be descended from the Bannatynes of Kames on the Island of Bute. (For a long time, the surnames of Bannatyne and Ballantyne/Ballantine were interchangeable.) During the 16th and early 17th centuries they possessed the lands of Castlehill, just east of the town of Ayr, but then they seem to have fallen on hard times, and Castlehill passed out of their hands. For most of the 17th and 18th centuries, the estate was in the possession of a branch of Ayr’s Fergusson family of merchants and lawyers, but they in turn faced ruin when the Ayr Bank of Douglas, Heron & Co. collapsed in 1772.
David Fergusson of Castlehill was provost of Ayr for much of the period between 1766 and 1791. His wife Elizabeth was the sister of John Ballantine, an Ayr banker who was a friend and patron of the poet Robert Burns and who was provost himself 1787-89, 1793-95, and 1796-98. John was instrumental in the building of Ayr’s New Bridge and the creation of Ayr Academy. By the time David Fergusson died in 1791, Castlehill had come back to the Ballantine family through his intermarriage with them. It was possessed first by John’s brother Patrick Ballantine, a merchant, who replaced the old mansion house there with a fine new one in 1804. When Patrick died in 1810, Castlehill and its mansion passed to John, who died in 1812.
The estate continued to be owned by the Ballantines and their relations until 1909, when it was purchased by William Wilson. Wilson was a muslin manufacturer from Paisley. He arrived in Ayr around 1900 and took up residence in Castlehill House as a tenant before buying the estate. He died in 1933, and a stained-glass window commemorating him can be seen in Alloway Church – he and other family members lie in the burial ground there. He was succeeded at Castlehill by a son, Glasgow stockbroker Leslie Hamilton Wilson (1884-1968). Another window in Alloway Church commemorates his son Leslie Cowans Wilson, killed in a plane crash at Prestwick Airport on Christmas Day 1954. In 1935 the estate passed into the possession of Castlehill Securities Ltd, but there continued to be a family presence in the mansion.
During the Second World War the house and estate were taken over by the Army. Plans to build a military barracks there in the mid 1950s were dropped, and the estate was eventually purchased by the local health board. They planned to build a new hospital on the site of the now-derelict 1804 mansion house, which was demolished in the mid-to-late 1960s, but after long delays another site was chosen for the hospital. In the early 1990s the estate was acquired by Kyle & Carrick District Council, and it is now a public park.