Tillycairn Castle is a 16th Century tower house built of granite walls which are harled externally in traditional style with dressings of Corennie granite to windows etc, under a Scotch slate roof. The roof line has fine turrets on each corner and a flat promenade area giving splendid views over the surrounding countryside. Architecturally the castle has links with the Bell family who are also associated with Castle Fraser, Craigston Castle and Cluny Castle. It is a Grade A listed property, reflecting its architectural and historical importance. Tillycairn is laid out over five floors reached by a spiral stone stair with a private servants stair.
On the ground floor is a substantial arched door with adjacent wide mouthed gun loop leads to the porters lodge, cloakroom and utility area and a passage through to the dining room with a barrel vaulted stone ceiling and large stone fireplace. From the dining room a door leads into the kitchen with three recessed gun loops with oilettes, amidst the normal kitchen accoutrements. First floor - Great Hall Large stone fireplace with Lumsden heraldic display, 4 windows to S&W with panelled shutters, stone flagged floor. Door through to the Laird's room, stone vaulted ceiling, open fireplace and coned ceiling boss showing the Arma Christi, fitted bookcase.
The lands of Tillycairn were the marriage portion of Annabel Forbes, daughter of the 6th Lord Forbes, on her marriage in 1540 to Matthew Lumsden. Matthew built Tillycairn Castle and further strengthened the fortifications of the castle following its pillage by John Strachan of Lynturk in June 1542. Further alterations and the addition of battlements were made by John Lumsden, 2nd Laird of Tillycairn, following his father's death in 1580. The castle as altered by John of Tillycairn survived until about 1722 when it was described as being derelict. In 1980 David Lumsden (XIX) of Cushnie and a family descendant of Matthew Lumsden, began the daunting task of rebuilding and renovating the castle which had been an uninhabited and roofless ruin for some 260 years. The property as it exists today is the result of a two year rebuilding programme and has faithfully recreated John Lumsden's castle of the 16th Century, but at the same time incorporating all modern facilities, but in a manner fully consistent with the castle's original design.