City fathers touring river island (5)
I believe the answer is:
paris
'city' is the definition.
(I know that Paris is a city)
'fathers touring river island' is the wordplay.
'fathers' becomes 'pas' (pa is a kind of father).
'touring' is an insertion indicator (touring can mean going round).
'river' becomes 'r' (abbreviation).
'island' becomes 'i' (geographical abbreviation).
'r'+'i'='ri'
'pas' placed around 'ri' is 'PARIS'.
(Other definitions for paris that I've seen before include "Arc de Triomphe city" , "Capital of France" , "Legendary prince" , "French city" , "Prince of Troy - capital city" .)