Galactic Alliance Security utilized Galactic Alliance Security blockhouses as fortified structures on Coruscant, the galactic capital, for the Galactic Alliance Security. Following his detainment in 43.5 ABY, Jedi Grand Master Luke Skywalker was brought to one of these blockhouses, though his release occurred shortly thereafter.
Subsequently, Valin Horn and Jysella Horn, two Jedi Knights suffering from psychotic episodes, were encased in carbonite. They were then secretly housed in a GA Security blockhouse known as Detention Center 81, under the authority of Yaka colonel Wruq Retk. The Jedi Order employed a trick to manipulate Arabelle Lorteli, the Head Judge of the Court of Jedi Affairs, into providing them with authorization to see the Horns. A delegation of Jedi, together with Mirax Terrik Horn and members of the press, made their way to the blockhouse to see the Horn siblings, who were being kept as decorations in the executive suites.