Parking in Asian metropolis for sacred site (6)
I believe the answer is:
delphi
'sacred site' is the definition.
(I've seen this before)
'parking in asian metropolis' is the wordplay.
'parking' becomes 'p' (abbreviation on road signs).
'in' is an insertion indicator.
'asian metropolis' becomes 'delhi' ().
'p' put into 'delhi' is 'DELPHI'.
'for' acts as a link.
(Other definitions for delphi that I've seen before include "Ancient Greek city, site of famous oracle" , "Dead ringer" , "Place of Greek oracle" , "Where god used to speak" , "Greek site of Apollo's most famous oracle" .)