What am I?

I can’t go left, I can’t go right. I am forever stuck in a building over three stories high. What am I?

related riddles

I cannot be burned in fire or drowned in water. What am I?

In the ground I am nothing, but give me time and I'll be something. What am I?

I am a protector. I sit on a bridge. One person can see right through me. Others wonder what I hide. What am I?