Firs do make attractive features in Norway (6)
I believe the answer is:
fiords
'features in norway' is the definition.
(I've seen this before)
'firs do make' is the wordplay.
'make' indicates anagramming the letters.
'firs'+'do'='firsdo'
'firsdo' anagrammed gives 'FIORDS'.
'attractive' acts as a link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for fiords that I've seen before include "Long narrow sea inlets in Norway" , "features in Norway" .)