一行は峻険な山道を一歩一歩登っていった。
The party climbed the steep mountain path one step at a time.
この地方は峻険な山々に囲まれ、冬は外部との交通が途絶える。
This region is surrounded by precipitous mountains, and in winter it is cut off from the outside world.
城は峻険な崖の上に築かれ、攻め落とすのは難しかった。
The castle was built atop a sheer cliff, which made it difficult to take.