This is going to be a very vague description of a small part of an animated children's TV movie/series of sorts (I can't even remember if it was a movie or just a cartoon short). I remember watching this sometime in the early 80's... '83 or '84 probably, on regular old TV: no cable. All I can recall is a boy (maybe a girl too) went through some sort of magic porthole (may have been a tree trunk they jumped down) and it took them to this underground world where various (mostly friendly) "monsters" lived but the monsters were in cages and they were trying to set them free. I want to say that the boy had red hair and glasses but not positive. Any info would be helpful, I've been trying to find out the name of this for the past five years at least! Thanks in advance!

Not sure, did some looking and found maybe Jamie and the magic torch??
The name does not sound familiar to me though but your desription does.

Yeah sounds like that to me from what I remember there was nutmeg the girl and wordsworth the dog remember that as it is my friends last name

Is this it click/copy the link
YouTube - JAMIE AND THE MAGIC TORCH

I watched the YouTube video, not ringing a bell with me. The animation was more along the lines of old Disney animation (versus the kind in Jamie and the Magic Torch). I know when the boy comes down the magic hole/slide it goes down a hallway with the cages full of monsters on either side of the hallway. I'm sorry I can't give more of a description than that... it's been so long ago! :)

I actually found out what it was by doing a "similar" search to Jamie and the Magic Torch. It is "The Secret World of Og" and it was 3-part special on ABC (Hana Barbara). I was actually able to find a DVD on eBay!

Never heard of that one