Behold the Supermen
A meta human prison located in Gruinard Island it houses all of the meta human criminals caught in Britain.
It has 5 floors above ground and an unclassified amount of basement levels.
No-one has ever escaped without outside help.
The Prison Guards are known as the Turnkey. Each cell is commonly referred to as a cage despite very few being actual cages.
Each cage is designed for the prisoner in mind and either negates their power or makes it useful to the den in some way.