Auchmull Castle was built by the Lindsays of Edzell in the late 16th century. Consisting of a square tower measuring around 9 metres by 9 metres, it was occupied until 1772 – latterly as a farmhouse – after which it was robbed for building materials and deteriorated rapidly.
The west wall and parts of the north and south walls still stood to a height of almost a metre by 1860, but by 1881 the castle had disappeared completely.
A stone from Auchmull Castle was discovered built into a nearby cottage in the mid 18th century, and can now be seen at Edzell Castle. Bearing the date 1601, it features two heraldic shields, the upper displaying the Lindsay arms and the lower the Wishart arms, with the initials D.L. and M.W. These initials are for David Lindsay and his wife Margaret Wishart.
Nothing is now visible on the site.