Crypts.
Aldrich had only ever heard about them on the Net as urban legends. Supposedly, they were deep pits far underground where uncontrollable threats were essentially just buried. Threats that just had no way to be dealt with normally.
Villains that were too unstable and powerful to ever see the light of day without being a threat to society were cast down into Crypts and just locked up forever. Alters or Variants that could not die by any conventional means were also sent down into Crypts to essentially just be sealed away until time immemorial.
Often times, Crypts were reused again and again, tossing in villains and variants into the same forsaken pit for them to brutalize each other.
The biggest reason why Crypts were considered urban legend despite their name and function being mentioned from leaked government documents was due to the fact that nobody had ever found a Crypt.
"A Crypt? Are they trying to kill me?" said Aldrich.