Pleasant part of Greece - or Sydney! (7)
I believe the answer is:
arcadia
'pleasant part' is the definition.
'arcadia' can be an answer for 'part' (I have seen 'part of Greece' mean 'arcadia' so perhaps 'part' could also mean 'arcadia'). I'm not sure about the 'pleasant' bit.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for arcadia that I've seen before include "Jumbo manufacturer" , "pastoral country" , "rural area" , "Idealised rural region" , "Idealised rustic paradise" .)