Most people think that Gahanna is hell or like hell, but it is not. "There is no evidence that animals or humans were thrown into Gehenna to be burned alive or tormented. So the place could not symbolize an invisible region where human souls are tormented eternally in literal fire." The same goes for hell, but "Gehenna was used by Jesus and his disciples to symbolize the eternal punishment of “second death,” that is, everlasting destruction, annihilation.—Re 20:14; Mt 5:22; 10:28." Curiosity of JW.org. You should check it out when you have some time or maybe if you want more information on the matter.
I think it was thought up with as much truth as the following:
"The house of Lies"
These are all versions of "Hell" assigned BY MAN to other religious myth . . . Have to have something to threaten would-be transgressors with . . .
Look them up, they are the "stick" for each of their perspective belief systems.
A bit chewy.