Perfect area to climb missing old country (7)
I believe the answer is:
Here is my best explanation:
'country' is the definition.
(Nigeria is an example)
I can't explain the rest of the clue.
(Other definitions for nigeria that I've seen before include "West African nation", "Country bordered by Benin, Niger, Chad, and Cameroon", "West African state", "African country r", "West African country, capital Lagos", "In rage I turn to this country", "W. African country", "Republic in West Africa", "part of Africa" and "Possible home for African".)