Anecdotes

Movie debut of Barbara Eden.

Remake of RKO's Quels seront les cinq? (1939), starring Chester Morris and Lucille Ball.

The twin engine plane that crashes is a Douglas DC2 built in 1935. It is still registered in Texas as active by the FAA.

The process of head-shrinking is well-known and is documented as being practiced by certain indigenous tribes in the northwestern Amazon jungle. The technique described en route by Vasquel (Rod Steiger) for preparing a severed head is accurate.

Though it is not the destination in the film, there is a town called Boca Grande on Gasparilla Island, off the west coast of Florida, south of Tampa.