Answer:
Upon me you can tread, though softly under cover. And I will take you places, that you have yet to discover. I'm high, and I'm low, though flat in the middle. And though a joy to the children, adults think of me little.
Who works when he plays and plays when he works?
What flies without wings? What passes all things? What mends all sorrow? What brings the morrow?
What zips through the sky with a tail of fire and dust. It could be an omen, its origin to discuss?
What can touch someone once and last them a life time?
What sphinxes employ and players enjoy.