Maria's unit developed a health farm (10)

I believe the answer is:

sanitarium

I'm a little stuck... Click here to teach me more about this clue!

'a health farm' is the definition.
The definition suggests a singular noun which matches the answer.

'maria's unit developed' is the wordplay.
'developed' indicates an anagram.
'marias'+'unit'='mariasunit'
'mariasunit' is an anagram of 'SANITARIUM'.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

Want a hint initially instead of a full solution? Install my app