Keys.

Symbolism can make even the most mundane objects interesting. And the key is about as mundane as you can get. We use them every day without a second thought. But the key doesn’t have to be a shaped object to fit into the lock of a door, or a safe, or a chest. And they can mean far more than to open something.
The rusty lock curling, taunting, on an ancient oak door,
The gleam of a silver safe that whispers of more,
Secrets that beckon beyond the physical veil,
Holding wealth or promises of a pretty old tale.
The hawthorn of the fey jagged, dangerous and black,
Takes you to a land from which you cannot come back.
The great Yggsdrasil, Norse world wise tree,
Odin hung from his throat from it for his mind to be free.
The heart is a prisoner that begs to be free,
And who is the locksmith that holds the key,
To the mysteries of life, or the path down to hell,
The past and the future, and your own personal cell.