Answer:
I am the red tongue of the earth, that buries cities.
They keep secrets locked away. And you pass through them each day. For each one there is a key, They respond to sesame.
One strand dangles. Two strands twist. Three or more can fashion this.
What leaps one time out of four?
Handy when you need to measure something or run a kingdom.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?