The Mego Lost Continent Box had two versions, this one explains that this playset would also be good for Mego "Planet of the Apes" figures. Apes were easily out selling AJ at the time.

The back of the box features a classic litho!

Would you like to touch Action Jackson's Monkey? Actually, he's a gorilla and Mego included him in the Jungle house as well. Which was a great idea.

IDOL HEAD IS PART OF A MECHANISM DESIGNED TO HOLD THE JUNGLE HOUSE STAIRS IN PLACE.
Here, it mounts through a hole in the cave floor and serves no practical purpose.

EXAMPLES OF CARDBOARD STAND UP CREATURES