Port of Norway (4)
I believe the answer is:
oslo
'port of norway' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for oslo that I've seen before include "Northern city" , "Scandinavian city" , "where Ibsen lived under another name" , "Scandinavian capital" , "Capital in throes of go-slow" .)