A "Butlin's" creation in Turkish city? (8)
I believe the answer is:
istanbul
'turkish city?' is the definition.
(I've seen this before)
'a butlin's creation in' is the wordplay.
'creation' indicates anagramming the letters.
'in' is an insertion indicator.
'butlins' is an anagram of 'istnbul'.
'a' inserted into 'istnbul' is 'ISTANBUL'.
(Other definitions for istanbul that I've seen before include "Catch the Latin bus out to Turkey" , "European city" , "foreign port" , "City straddling the Bosporus" , "Modern name of Constantinople" .)