Stuck on the ledge in Oz

Through the Oz door, Seymour lands on a ledge in THE WIZARD OF OZ with walls all round. Where now?
Nudge 1Where to look
If you can't go along, go down.
Nudge 2A stronger push
There's a hole: it drops into MUNCHKIN VALLEY. Watch the ground there.
Nudge 3Almost there
From MUNCHKIN VALLEY a block in the middle lets you jump back up into the Oz room's lower floor.
What you needOther problems to solve first
Solve these first (each opens its own page, no answers on the way):
Show the solutionThe whole answer, with a video
Drop down the hole into MUNCHKIN VALLEY, jump up from its middle block into the lower floor of THE WIZARD OF OZ, and walk left into CASTLE EXIT. From there you can climb up to THE CASTLE TOP, and OVER THE RAINBOW joins the castle top to the upper left of the Oz room. CASTLE EXIT's door leads back out to the maze. Its floor has a nasty stretch in the middle: jump it.