Rock garden overlooking a Caribbean location (7)
I believe the answer is:
grenada
'caribbean location' is the definition.
(Caribbean island)
'rock garden overlooking a' is the wordplay.
'rock' indicates anagramming the letters (the solver must 'rock' the letters around).
'overlooking' is an insertion indicator (in a down clue, some letters go above others).
'garden' is an anagram of 'grenda'.
'grenda' going around 'a' is 'GRENADA'.
(Other definitions for grenada that I've seen before include "West Indian island" , "Caribbean country, capital St George's" , "Commonwealth country" , "Caribbean island country" , "Island N. of Trinidad" .)