Shifting, Shifting, Drifting deep.
Below me great and mighty cities sleep.
Swirling, Scurlling, All around.
I'm only where no water will be found.
With my pair I should be,
But I am usually alone you see,
For a monster always eats me.
Do you know what I must be?
Select a pack of riddles and try to solve it in an interesting way.
This riddle appears in the following downloadable PDF files: