The estate, including the old castle, was purchased in the late 17th century by Sir
Thomas Kennedy of Kirkhill,
Lord Provost of Edinburgh, and occupied by his son
Thomas Kennedy of Dunure. Over the years, the old castle has also been known as Dalqhrin, Dahuharra Castle, Old Place of Dalwharn, Dolquharran. Kennedy of Kirkhill also bought
Dunure Castle and its estate. Thomas Kennedy of Dunure was the husband of
Robert Adam's sister, The castle was arranged symmetrically around a central entrance hall, with top-lit central spiral staircase similar to
Culzean Castle, which Adam designed for David Kennedy from around 1776. The house has four floors, with bedchambers in the two floors. The interior was decorated in a classical style. Services were located in the basement. A round bastion turret in the south front contains a drawing room on the ground floor, with library above, with views over Girvan Water. A large oval dining room occupies the east wing on the ground floor. When the castle was completed in 1790, Thomas Kennedy moved out of the old castle which was abandoned and stands in ruins nearby, about southeast, closer to the river. Dalquharran Castle (Old Castle) became a listed monument in 1935 as "the remains of the old castle of Dalquharran, surviving as substantial standing structures and as buried archaeology, together with an area enclosing the outer defences and infrastructure". That report states that it was "originally a rectangular keep ... greatly enlarged and converted into a "stately castle" in about 1679". To the north of the castle, Adam designed a long low stable range connected at either end to the main building by screen walls with gateways, creating a forecourt. The outbuildings were constructed in a simpler style than originally designed by Adam, possible after his death in 1792, with several small lodges arranged symmetrically around the court. ==19th, 20th and 21st centuries==