The Zigursky Penitentiary is the maximum security prison in Paragon City designed to house super-powered criminals. It's also known as "The Zig", "The Big Zig", the "Ziggurat", and "The Brick" (the original nickname of the prison).
For several years, the prison was the subject of frequent break-outs by the criminal organization Arachnos in their attempt to recruit new operatives as a part of "Project Destiny". Despite efforts by Freedom Corps forces to contain the breakouts, there was a continual bleed of prisoners which endangered the whole Brickstown district.
The seemingly endless breakouts were the subjects of media ridicule, not to mention continual calls from certain people for more stringent measures and the firing of the prison warden.
Finally, in early September of 2011, the orchestrated breakouts came to an end, thanks in no small part to the efforts of newly-elected District Attorney Alex Wentworth and a forced change in administration. There would still be escapes, but those escapees would have no place safe for them to flee to anymore.
(Please see its Paragon Wiki entry for more information.)