In 2009, an Israeli cave researcher discovered an ancient necromancy cave that was once believed to be a portal to the underworld. 

This month the Harvard Theological Review published over a decade of studies from the Israel Antiquities Authority and Bar-Ilan University. 

Hidden deep in Te'omim Cave in Jerusalem, researchers have discovered evidence of ritual magic practices left behind in ancient times.  All the finds date back to the late Roman and early Byzantine periods.

Found in the cave were indications of dark magic ceremonies.  And the researchers believe this is where necromancers attempted to conjure the spirits of the dead.

Necromancy also known as “death magic” was the practice of sorcery involving communications with the dead by summoning their spirits as apparitions or visions. And the cave was once considered a portal to the underworld, an oracle, and a physical representation of a Chthonic deity. It was where ancient witches dedicated their ritual magic.

Necromancy cave 

Boaz Langford’s discovery in the Judean Hills, Israel, unearthed 120 gold, silver, and bronze coins, several 2,000-year-old human skulls, 120 oil lamps, and ceremonial daggers. No additional human bones were discovered with the skulls.

These artifacts were likely used as part of necromancy ceremonies in the cave during the Late Roman period, the authors concluded after reviewing their discoveries and a library of ancient papyrus scrolls from the era, which detailed spells and customs honoring the cave.

"One spell explains how to restrain and seal the mouths of skulls so that they won't say or do anything. Another shows how to raise the spirit of the dead with a disinterred skull: a spell is written in black ink on a flax leaf, which is then placed on the skull," Boaz Zissu wrote.

 "The purpose of another spell is to obtain assistance and protection from spirits by using the skull of Typhon (probably a donkey) on which a spell is written in the blood of a black dog."

There was no evidence of live sacrifices. The daggers and other weaponry found in the cave were talismans to protect against the spirits. And they were made specifically of iron or bronze because evil spirits were believed to have feared metal.

The research study also claimed that human sacrifice was outlawed in 97 BCE by the Roman Senate. By 357 CE, the researchers note, necromancy was also condemned by the emperor Constantius II. He banned "all forms of divination, communication with demons, disturbance of the spirits of the dead, and nocturnal sacrifices."