Criminal left soldiers inside city (8)
I believe the answer is:
florence
'city' is the definition.
(Florence is an example)
'criminal left soldiers inside' is the wordplay.
'criminal' becomes 'fence' (I've seen this before).
'left' becomes 'l' (common abbreviation).
'soldiers' becomes 'OR' (Other Ranks).
'inside' is an insertion indicator.
'l'+'or'='lor'
'fence' placed around 'lor' is 'FLORENCE'.
(Other definitions for florence that I've seen before include "City on R. Arno" , "Name of girl ? city" , "Nurse Nightingale in Italian city" , "Brunelleschi's birthplace" , "___ Nightingale, the Lady with the Lamp, d. 1910" .)