Answer:
So cold, damp and dark this place. To stay you would refrain, yet those who occupy this place do never complain.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.
I scribble forms of the finest letter, And repel elements of the harshest weather. I am an arrow-aimer and a dust-breaker.
What is full of holes, but can still hold a lot of water?
I march before armies, a thousand salute me. My fall can bring victory, but no one would shoot me. The wind is my lover, one-legged am I. Name me and see me at home in the sky.
It's what light turns into in the night