Answer:
What has two legs but doesn't walk?
I am the red tongue of the earth, that buries cities.
I am a box that holds keys without locks, yet they can unlock your soul.
Thirty white horses on a red hill, first they champ, then they stamp, then they stand still.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?
What is so fragile that saying its name breaks it?