Answer:
A box without hinges, lock or key, yet golden treasure lies within.
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
What do you throw out to use and take in when you're done?
It stands upright and can be quite grand. Its secret is not hidden but right at hand. What is it?
It's like food but water kills it. What is it?
A mysterious, fantastic creature, It has one defining feature, And for humans at their worst, In their eyes it's just a horse