mountainous
Mountainous is an adjective.
The terrain was mountainous.
it is mountains
Iceland is mountainous.
Yes, South Korea is mountainous.
Yes! Most of all Kosovo is mountainous !
Mountainous Croatia's population is 90,643.
Switzerland is noted for its mountainous terrain.
The word for mountainous in Spanish is: montañoso.
Zurich, Gstaad and Berne are all mountainous.
Not really, although Wales is quite mountainous