Gehenna is a place of misery, or a state of misery.
Gehenna is derived from the Greek word Geenna and Hebrew place name Hinnom.
Gehenna literally refers to the Valley of Hinnom.
In the doctrine of last things, Jewish and Christian eschatology, Gehenna is the abode of the damned, afterlife place. In the Bible, the Valley of Hinnom is near Jerusalem where refuse was dumped and fires were kept continually burning to prevent pestilence. As a result of this, continually burning, Hinnom is referred as a place of torment, and burning. In the New Testament, Gehenna is noted as hell, due to this the word is also referred to ‘hell’.
In the Hebrew Bible, Gehenna was the place where the Kings of Judah sacrificed their children by fire to the Ammonite god Moloch, so, it was deemed to be cursed. But the sacrificial practice continued till Babylonia exile in the sixth century and was later turned to a garbage centre.
According to rabbinic literature, it is the destination of the wicked, a Purgatory, a place where one becomes aware of one’s shortcomings and negative actions before exiting the earthly life. One’s stay here is temporary. Gehenna is not equated with Sheol, Hades.
In the modern day, the Valley of Hinnom is the valley surrounding Jerusalem’s old city and Mount Zion and merges with Kidron Valley.