Leaning Tower city (4)
I believe the answer is:
pisa
'leaning tower city' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pisa that I've seen before include "Location of leaning tower" , "Site of the famous leaning tower" , "much-visited city" , "listed building site" , "City on the River Arno" .)