Two at a remarkable city (6)
I believe the answer is:
ottawa
'city' is the definition.
(Ottawa is an example)
'two at a remarkable' is the wordplay.
'remarkable' indicates an anagram.
'two'+'at'+'a'='twoata'
'twoata' with letters rearranged gives 'OTTAWA'.
(Other definitions for ottawa that I've seen before include "North American city" , "Canadian city" , "Canadian capital" , "The capital of Canada (6)" , "N. American city" .)