Rough, rugged (6)
I believe the answer is:
craggy
I believe this clue is a double definition.
'rough' is the first definition.
(similar in meaning)
'rugged' is the second definition.
(synonyms)
(Other definitions for craggy that I've seen before include "Rocky and steep" , "Hilly; rugged" , "Mountainous" , "with rough faces" , "Weather-beaten" .)