"The church of the united parish now stands at the village of Dreghorn, which is pleasantly situated on a gentle eminence a short distance south of the water of Annick, and two miles south-east of the town of Irvine. The site of the church has been happily chosen in regard to airiness and picturesque effect. It was built in 1780, and is a neat, though unadorned building of octagonal form, with a double row of equilateral arched windows. A steeple is attached to the south side of the structure. In regard to accommodation, it is capable of holding, comfortably, 427 sitters."
"The greater part of the walls of the old church of Pierstoun are yet entire. It is situated on a densely wooded knoll overlooking the Water of Annick, and about a mile and a half north of the village of Dreghorn. The interior of the ivy-mantled ruin contains the burial places of the families of Pierstoun and Cunninghamehead."
"Ayrshire Nights Entertainment: A Descriptive Guide to the History, Traditions, Antiquities of the County of Ayr" by John MacIntosh of Galston, Ayrshire, published in 1894, by John Menzies & Co. of Kilmarnock, Dunlop and Drennan.
There is a photograph of Dreghorn parish church together with a short history including some words about the origin of its unusual octagonal shape, and references to other such churches.