This stronghold is part of a trinity of Maths Mafia fortresses, the other two being Minas Maths and Minas Music. The Mafia use Stock Castle as the base for their attempts to hijack the Galactic Economy and pollute the League's Political System.
Much like any castle, Stock Castle consists of a main wall, a keep and an armoury. The armoury is filled with machines of war such as the Ka-Ching 9000 which is Fart Reel's primary weapon.
It is unknown who actually built the castle initially, although it is assumed that the Mafia themselves did not build it. Its architecture resembles Ancient European Castle Construction, but on the inside it has been transformed with Maths Mafia technology.