Adjacent to the Puente de Isabel II, the Castillo de San Jorge is steeped in notoriety: it was here that the infamous Spanish Inquisition had its headquarters from 1481 to 1785. When the Inquisition fires were finally doused in the early 19th century, the castle was demolished and a market built over its ruins. These remains were subsequently rediscovered in 1990, and they now house a museum illustrating the Inquisition's activities and life in the castillo.

　　Walkways lead through the underground ruins with panels juxtaposing details of each room’s function with chilling accounts of the Inquisition and its victims.