Incarcecon

Incarcecon is a completely artificial prison planet built only to keep alien criminals safely held. There are no rules there, it's only suvival of the meanest. Some known aliens and alien species reside there: Myaxx, Sixsix, and some species of aliens such as Tetramand, Piscciss Volann, and Lepidopterran. Galvanic Mechamorphs are also set there for maintenance and general repair.

It is apparently composed of many different branches (As confirmed by Dwayne McDuffie).

One of Incarcecon's many branches appeared Ben 10: Ultimate Alien episode "Nor Iron Bars a Cage." It is more like an asteroid in this form. The prison that appeared in Vendetta may have also been that Incarcecon branch judging by appearance. Because of the corruption that has been going on and the damaged done and its prisoners escaping its likely that facility will be transferred into plumber jurisdiction and its likely now the plumbers will have to find and recapture the escaped prison inmates from Incarcecon that are now loose and reforms will likely be made concerning matters in the Null Void.

Security Measures
To enter Incarcecon, you have to enter a code. Additionally, once a warden finds out that you are trying to rescue a prisoner, they'll fire at your ship and send out security drones to stop you.