Perfect area to climb missing old country (7)
I believe the answer is:
nigeria
'country' is the definition.
(Nigeria is an example)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for nigeria that I've seen before include "Country bordered by Benin, Niger, Chad, and Cameroon" , "Possible home for African" , "W. African country" , "African country, capital Abuja" , "African republic, capital Abuja" .)