Green’s Dictionary of Slang

(Aus.) a psychiatric institution.

1904		H. Fletcher Dads Wayback: His Work 35: No one out o’ Callan Park, or who ought ter be there, ever does take it that way [GAW4].
1952		J. Cleary Sundowners 157: They’d just think the long-legged bastard was off his rock and ring up Callan Park.
1959		D. Hewett Bobbin Up (1961) 208: Life’s hard enough for everyone without puttin’ up with a mad kid inter the bargain [...] You feel as if you’re orf to Callan Park yourself.
1982		Sydney Morning Herald 10 Apr. 23: Why I’m not in Callan Park I’ll never know [GAW4].