The crow-stepped upper storey was a doocot (dovecote) to house pigeons belonging to Balfour Castle. Doocots were common on wealthy estates up until the mid-Victorian period. The birds were given shelter in the tower and protection from vermin. Often the outer walls of a doocot have one or more horizontal ridges, which prevent rats from climbing up the outside. The pigeons were a source of meat and eggs, and their droppings were used as fertiliser. The tower also housed a saltwater shower for the wealthy inhabitants of the castle.
“On the top there was a huge cistern which was pumped full of sea-water and therefrom there descended inside the tower a pretty wide wooden tube by which the water could be let down in a powerful douche.” (From George Balfour Kinnear’s ‘Recollections’)
The ‘Point of Dishan’ is the promontory on which the tower sits, hence the name ‘Dishan tower’.