Not so much a mystery, but more of a gruesome custom of the Shuar Indians of the Amazon regions of present day Ecuador and Peru. A shrunken head is a real human head, ritually prepared for spiritual protection and intimidation. The Shuar did not collect the heads as trophies and had no interest in the heads themselves, but rather the soul of the victim that they claimed was contained inside the shrunken head.

Head-hunting occurred in many regions of the world, but the practice of head shrinking has only ever been recorded in the north-western region of the Amazon rain forest by the Shuar Indians. Among the Shuar, a shrunken head is known as a Tsantsa. The ritual was only documented once on film in 1961 by Edmundo Beilawski.

The shrunken heads were created by removing the skull through an incision in the back of the severed head. Fat from the flesh of the head is removed . The eyelids are sewn shut and the mouth held shut with splinters. The flesh is boiled in water with a mixture of herbs containing tannins, then dried using hot pebbles and sand. During the drying process the head can be molded and shaped accordingly. The skin is then rubbed down with charcoal ash. Decorative beads are added to the head and the lips were then sewn shut and decorated with beads and ribbons.

Piers Gibbon on behalf of National Geographic traveled to the Amazon in order to validate the 1961 footage of the head shrinking ritual. The film was found to be authentic. The special “Headshrinkers of the Amazon” first aired in 2009.