Parkour runners do a move where they run up walls and
back
down. This is a variation of that.
The wall would actually be a chimney opened on one half
that would rise perpendicular to the ground. The ground
would slope up to this wall allowing the runner a smooth
transition from horizontal
to vertical as they
tried to see how high up the chimney they could run.
The trick would be to know when you're going to lose that
momentum carrying you around the chimney so you could
turn and run back down staying on your feet. If you
misjudged, you would just stall out and fall flat on your
back. The curving of the wall into a chimney is to create
centrifugal force that the runner can tap to run higher up
the wall.
So to be clear, you'd run up to this thing in a vertical
position,
transition to horizontal as you ran up the wall and if you did
it right, turn around facing back down and run back down
transitioning again to vertical.
There would be numbered lines on the wall showing how
high you
got.
Based on RayfordSteele's story about an empty pool sort of
shaped like this in which the kids would run at various
angles.