Capital of Latvia seemingly obvious originally, looking north (4)
I believe the answer is:
oslo
'capital' is the definition.
(capital of Norway)
'of latvia seemingly obvious originally looking north' is the wordplay.
'originally' suggests taking the first letters.
'looking north' says the letters should be written in reverse (going up in a down clue).
The initial letters of 'of latvia seemingly obvious' is 'olso'.
'olso' backwards is 'OSLO'.
(Other definitions for oslo that I've seen before include "It's capital in Anglos London" , "Nordic city" , "European capital in go-slow" , "Norwegian city, formerly Kristiania" , "where Ibsen lived under another name" .)