US city built by characters from Orkneys (7)
I believe the answer is:
yonkers
'us city' is the definition.
(city in New York state)
'built by characters from orkneys' is the wordplay.
'built by characters from' indicates an anagram (built from the same letters or characters).
'orkneys' with letters rearranged gives 'YONKERS'.
(Other definitions for yonkers that I've seen before include "US city" , "place of New York" , "American city" , "NYC suburb" , "Hudson River city" .)