Answer:
Inside a great blue castle lives a shy young maid. She blushes in the morning and comes not out at night.
It's been around for millions of years, but is never more than a month old. What is it?
As a whole, I am both safe and secure. Behead me, I become a place of meeting. Behead me again, I am the partner of ready. Restore me, I become the domain of beasts.
Hands she has but does not hold. Teeth she has but does not bite. Feet she has but they are cold. Eyes she has but without sight.
You’ll have me at night and if you remove the first letter I denote the top, such as on a train
I’m grown from darkness but shine with a pale light. Very round I am and always a lady's delight.