A harvest and place to store it back in citadel (9)
I believe the answer is:
acropolis
'citadel' is the definition.
(acropolis is a kind of citadel)
'a harvest and place to store it back' is the wordplay.
I cannot quite understand how this works, but
'a' is found in the answer.
'harvest' could be 'crop' (synonyms) and 'crop' is found in the answer.
'place' could be 'is' (I've seen this in other clues) and 'is' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'in' acts as a link.
Can you help me to learn more?
(Other definitions for acropolis that I've seen before include "Citadel of an ancient Greek town" , "classical site" , "Imposing building" , "Parthenon location" , "high point" .)