Answer:
In many hallways you would stand, if not with this in hand.
What object has keys that open no locks, space but no room, and you can enter but not go in?
You fill it and it empties, A metaphor for plenty, Depending on what half you see, It's either full or empty
I travel the world and I am drunk constantly. Who am I?
Where can you find roads without cars, forests without trees and cities without houses?
I fly to any foreign parts assisted by my spreading wings. My body holds an hundred hearts Nay I will tell you stranger things when I am not in haste I ride and then I mend my pace anon.