What Am I?

What am I?

I do not know.

So please,

Won’t you tell me so?

Am I a room?

Am I a shelf?

Am I a building?

Or Santa’s elf?

Well, it depends,

I’d have to say,

On what you see of me,

This day.

I must be a treasure box,

Because there is treasure within me.

Although, you’d say no,

Because there is no gold you can see.

I must be the world’s secret keeper, 

Holding the secrets of the world, within.

But that can’t be right;

Everyone learns my secrets, by day or by night.

What am I indeed?

I can’t decide.

I know one thing, though;

I can’t hide.

I think I’ve got it.

I know what I must be.

Now say it with me;

I am a library.