There are two. Larnach Castle, occupied; and Cargill's castle, was derelict, but I don't know its current status.
Larnach Castle
Larnach castle
Larnach Castle is the best known, though there was also a Cargill's Castle to the south of the city. (Maybe currently derelict?) Larnachs Castle is a popular venue for weddings etc, and has fine gardens.
Larnach Castle, built in 1871 by William Larnach
Larnach Castle
Castle Street
Larnach
Six60 got their name from the flat where they started the band, 660 Castle Street, Dunedin, NZ.
baka
The Maori name for Dunedin is Ōtepoti.
Larnach Castle is situated on the Otago peninsular, near the city of Dunedin, in the South Island.
The forest outside Macbeth's castle is called Birnam Wood.