In 1527 the estate of Achynche (Auchans) was first held by the Wallaces of Dundonald.
Colonel James Wallace was the last of that family to occupy the castle; he was an active supporter of the Solemn league and Covenant and led the rising at Pentland in November 1666.
He died in exile in Rotterdam in 1678.
His family were a branch of the Wallaces of Craigie.
In 1640 the estate passed to his relative Sir William Cochrane of Cowdon, an arrangement carried out prior to Colonel Wallace's participation in the insurrection.

Sir William also suffered during the Civil War, but after the restoration of the monarchy he was created Earl of Dundonald in 1669 for his services to the Crown.
The second earl for a time lived with his mother, Lady Katherine Kennedy, at Auchans, after his father died, circa 1679.
Adamson relates ambiguously that the earl lost the estate due to unfortunate scientific speculations.
In 1876, it is recorded that one of the side angles had the date of 1644 and another of 1667; a marriage stone had the initials WCD (William Cochrane of Dundonald) and ES (Eupheme Scott) also occurred in two places.

After the death of Lady Eglinton in 1780, Auchans housed workmen's families.
Archibald, the 11th Earl of Eglinton lived here for a while at some stage.
The Dundonald cemetery houses the Auchans burial ground, next to that of Craighouse, Fairlie house and Shewalton House.
John Dunlop Esq.
of Whitmuir Hall near Selkirk has a memorial plaque, giving the fact that he was Factor to Lady Susanna Montgomery at Auchans and died in 1836, aged 61.
John Dunlop Esq.
is quoted by William Aiton as having set up and recorded rainfall with a rain gauge at Auchans House in 1808-1809.

In 1846 the property was owned by Lady Mary Montgomerie, by whose servants it was chiefly inhabited and it was becoming ruinous, with parts untenanted and locked up.
The structure was altered quite considerably to accommodate the workmen and some features, such as ornate marble fireplaces, were removed and taken to Auchans House, now demolished.
In 1875 estate foresters occupied the ground floor, but the roof was well maintained.
In 1885 stones had been take to build cottars houses however part of the west wing next to the north gable was re-roofed.
Janet Gilchrist, a single lady, was at the time employed as a caretaker and remained until 1897.

In 1892, following the death of Archibald William, the 14th Earl of Eglinton, his daughter Lady Sofia Constance Montgomerie inherited the Auchans estate that comprised the house and policies together with the farms of Bogside, Broomhill, Clevance, Crooks, Girtrig, Guilliland, Highlees, Kilnford, Laurieston, Parkthorn and Ploughland.

The building was able to be used during World War I to house German prisoners of war, however by 1922 the roof had largely collapsed.

Auchans was at one point re-acquired by the Earl of Dundonald, who owned Auchans House in 1951.
Attempts are occasionally made to restore the castle, including interest by the Clan Wallace Sociey.
In 1527 the estate of Achynche (Auchans) was first held by the Wallaces of Dundonald. Colonel James Wallace was the last of that family to occupy the castle; he was an active supporter of the Solemn league and Covenant and led the rising at Pentland in November 1666. He died in exile in Rotterdam in 1678. His family were a branch of the Wallaces of Craigie. In 1640 the estate passed to his relative Sir William Cochrane of Cowdon, an arrangement carried out prior to Colonel Wallace's participation in the insurrection.
Sir William also suffered during the Civil War, but after the restoration of the monarchy he was created Earl of Dundonald in 1669 for his services to the Crown. The second earl for a time lived with his mother, Lady Katherine Kennedy, at Auchans, after his father died, circa 1679. Adamson relates ambiguously that the earl lost the estate due to unfortunate scientific speculations. In 1876, it is recorded that one of the side angles had the date of 1644 and another of 1667; a marriage stone had the initials WCD (William Cochrane of Dundonald) and ES (Eupheme Scott) also occurred in two places.
After the death of Lady Eglinton in 1780, Auchans housed workmen's families. Archibald, the 11th Earl of Eglinton lived here for a while at some stage. The Dundonald cemetery houses the Auchans burial ground, next to that of Craighouse, Fairlie house and Shewalton House. John Dunlop Esq. of Whitmuir Hall near Selkirk has a memorial plaque, giving the fact that he was Factor to Lady Susanna Montgomery at Auchans and died in 1836, aged 61. John Dunlop Esq. is quoted by William Aiton as having set up and recorded rainfall with a rain gauge at Auchans House in 1808-1809.
In 1846 the property was owned by Lady Mary Montgomerie, by whose servants it was chiefly inhabited and it was becoming ruinous, with parts untenanted and locked up. The structure was altered quite considerably to accommodate the workmen and some features, such as ornate marble fireplaces, were removed and taken to Auchans House, now demolished. In 1875 estate foresters occupied the ground floor, but the roof was well maintained. In 1885 stones had been take to build cottars houses however part of the west wing next to the north gable was re-roofed. Janet Gilchrist, a single lady, was at the time employed as a caretaker and remained until 1897.
In 1892, following the death of Archibald William, the 14th Earl of Eglinton, his daughter Lady Sofia Constance Montgomerie inherited the Auchans estate that comprised the house and policies together with the farms of Bogside, Broomhill, Clevance, Crooks, Girtrig, Guilliland, Highlees, Kilnford, Laurieston, Parkthorn and Ploughland.
The building was able to be used during World War I to house German prisoners of war, however by 1922 the roof had largely collapsed.
Auchans was at one point re-acquired by the Earl of Dundonald, who owned Auchans House in 1951. Attempts are occasionally made to restore the castle, including interest by the Clan Wallace Sociey.
Auchans Castle, Ayrshire