In Harry Potter and the Cursed Child there is a riddle. While I can get a lot of it (indeed, a fair amount of it is explained by the characters themselves), I'm less confident about other bits, particularly the last third of the riddle. So, does anybody have a complete breakdown of the riddle?
The first is the fourth, a disappointing mark
You'll find it in parked but not in park.
The second is the less fair of those that walk on two legs.
Grubby, hairy a disease of the egg.
And the third is both a mountain to climb and a route to take.
A turn in the city, a glide through a lake.
(Harry Potter and the Cursed Child - pp.89-90 - Little, Brown - Act One, Scene Nineteen)