The Kyln is a fictional location

Fictional location

Fictional locations are places that exist only in fiction and not in reality. Writers may create and describe such places to serve as backdrop for their fictional works. Fictional locations are also created for use as settings in Role-playing games such as Dungeons and Dragons...

, a power generating-facility and maximum security prison in the .

A series of spherical containment units located by the galactic barrier (a.k.a. The Crunch

Big Crunch

In physical cosmology, the Big Crunch is one possible scenario for the ultimate fate of the universe, in which the metric expansion of space eventually reverses and the universe recollapses, ultimately ending as a black hole singularity.- Overview :...

) and maintained by interstellar races and various degrees of mechanical automation (flying robots, nanotechnology, etc.), its primary architect is unknown. Previous to the Annihilation

Annihilation (comics)

"Annihilation" was a 2006 crossover storyline published by Marvel Comics, highlighting several outer space-related characters in the Marvel Universe. The central miniseries was written by Keith Giffen, with editor Andy Schmidt.-Publication History:...

 Wave, it served two primary purposes:

1. Power generation & distribution to neighboring worlds. Presumably, the Kyln draws energy from the interaction of matter and anti-matter.
2. An inescapable, intergalactic prison known to hold very powerful prisoners inside. The scope and level of containment is unknown, as it has demonstrated the capability of holding thousands of very dangerous, biological entities (such as the Power Skrull
   Paibok
   Paibok the Power Skrull is a fictional alien, a comic book supervillain appearing in the Marvel Comics universe. He is a foe of the Fantastic Four. His first appearance was in Fantastic Four Vol...
   
    and Gladiator) along with cosmic Elder Gods, Tenebrous
   Tenebrous (Marvel comics)
   Tenebrous is a fictional character, a Marvel Comics cosmic entity appearing as an enemy of Galactus.-Origin and War:Shortly after the Big Bang of the Marvel universe, the Proemial Gods arose from the very universe itself, collectively existing to maintain the cosmic consonance between order and...
   
    of the Darkness Between and Aegis
   Aegis (Lady of All Sorrows)
   Aegis is a fictional character, a comic book cosmic entity published by Marvel Comics and appearing as an enemy of Galactus. Created by writer Keith Giffen and artist Andrea DiVito, the character first appeared in Annihilation: Silver Surfer #3...
   
    the Lady of All Sorrows. The latter pair were trapped there by Galactus
   Galactus
   Galactus is a fictional character appearing in comic books and other publications published by Marvel Comics. Created by writer-editor Stan Lee and artist and co-plotter Jack Kirby, the character debuted in Fantastic Four #48 , the first of a three-issue story later known as "The Galactus...
   
    prior to the construction of the technological prison. The Kyln also held an incarnation of the Beyonder
   Beyonder
   The Beyonder is a fictional character in . Created by Jim Shooter and Mike Zeck, the immensely powerful Beyonder first appeared in Secret Wars vol. 1 #1 as an unseen force. He reappears in Secret Wars II #1 , which was created by Jim Shooter and Al Milgrom.-Publication history:The Beyonder was a...
   
   .

Currently the Kyln is in ruins as a result of the Annihilation Wave

Annihilation (comics)

"Annihilation" was a 2006 crossover storyline published by Marvel Comics, highlighting several outer space-related characters in the Marvel Universe. The central miniseries was written by Keith Giffen, with editor Andy Schmidt.-Publication History:...

.