Answer:
I'm not a bird but I can fly through the sky. I'm not a river but I'm full of water.
You write on me and secrets I can keep. In places never seen. I spin like a top. Though stiff as a board I'm often described like a mop.
Against the sun I protect your eyes and am often worn on the face of spies
The Titanic is still here.
Who is the most foreign visitor you could imagine?
A little house full of meat, no door to go in and eat.