This is a nice walk.
Ruined, but well preserved, Fairlie Tower is a plain 15th century keep of four storeys with a later corbelled-out parapet and wall-mounted turrets. The walls are pierced by gunloops. The castle was built by the Fairlie family, but sold to the Boyle family of Kelburn estate in 1650.
There’s no access to the interior as the entrance is blocked up.
If you continue up the path you will come to a waterfall.