The Mysterious Key

On Monday, we left Mary in The Secret Garden with a newly found key. She uncovered it with the robin's help.

On Tuesday, Levi was working on the twig structure during Art, and he found the key in the photo to the left. Isn't that magical?

Later on that same day, Mary unlocked the secret garden! The timing was marvelous!

We've been discussing the symbolism of a key.
What does a key symbolize to you?