There are and have been several bands named Gehenna, the most notorious of which are the following:

1) A black metal band from Norway.

1) A black metal band that was formed in Stavanger, Norway in January 1993 as a nameless project by Sanrabb, Dolgar and Sir Vereda. They didn’t give the band a name until they had enough material which would represent their voice. In May of the same year, the trio entered the studio to record a demo. Sanrabb and Dolgar shared the duty of guitars, vocals, bass and synth, while Sir Vereda took his seat behind the drum set.

The demo was recorded between the 3rd and 7th of June 1993 in Soundsuite Studios. It was released under the name “Black Seared Heart” as a tape limited to 100 copies.

Gehenna participated in the Darkthrone tribute “Darkthrone Holy Darkthrone”, released by Moonfog Productions in 1998, covering the song “Transilvanian Hunger”. Later, in 2001, the band also participated in the Mayhem tribute “Originators of the Northern Darkness: A Tribute to Mayhem”, released by Avantgarde Music, covering the song “Cursed In Eternity”.

After several years of inactivity, the band returned with "WW" in 2005, heralding a much welcomed return to their black metal roots.

Eight years later, in 2013, Gehenna released Unravel.

Discography:

Black Seared Heart Demo, 1993
Ancestor of the Darkly Sky EP, 1993
First Spell mini album, 1994
Seen Through the Veils of Darkness (The Second Spell) Full-length, 1995
Malice (Our Third Spell) Full-length, 1996
Black Seared Heart Best of/Compilation, 1996
Deadlights EP, 1998
Adimiron Black Full-length, 1998
Murder Full-length, 2000
WW Full-length, 2005
Unravel Full-length, 2013

http://www.myspace.com/gehennaofficial

2) A Death/thrash metal band from Finland that formed in 1994 and changed their name to Riivaaja in 1996.

3) A Mexican progressive power metal band formed in 1979. They are apparently still active, although their last album (their 2nd altogether) was released in 1987. http://www.myspace.com/officialgehenna

4) A Swedish Black/Thrash Metal band. They formed as Gehenna, but after one demo called "Kill" (1993) changed their name to Gehennah.

5) An American Death Metal band from Salix, Pennsylvania that released one demo called "The Horror Begins..." in 1991. http://www.myspace.com/gehennapa Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.