Greek city corners recalled Athens at first (6)
I believe the answer is:
sparta
'greek city' is the definition.
(I've seen this in another clue)
'corners recalled athens at first' is the wordplay.
'corners' becomes 'traps' (I've seen this before).
'recalled' shows that the letters should be reversed in order.
'at first' indicates taking the first letters.
The first letter of 'athens' is 'a'.
'traps' back-to-front is 'spart'.
'spart'+'a'='SPARTA'
(Other definitions for sparta that I've seen before include "Laconic state" , "found in Ancient Greek location" , "Where to find ancient Greek" , "Ancient kingdom renowned for asceticism" , "in ancient Greece" .)