The old prison and council building of the town of Martos is now its town hall. It is one of the jewels of Mannerist Spanish architecture.
This Renaissance Mannerist building is the work of the architect Francisco de Castillo “el Mozo”. It is designed on a rectangular plan on two floors, with numerous rooms and spaces laid out around a central courtyard. The doorway and its lintel on its main façade is of particular artistic interest. It opens between two joined Doric columns and under an entablature-frontispiece presided over by the coat of arms of the Hapsburgs and flanked at the top by two sculptured figures representing Justice and Prudence (now without their heads). Coats of arms, inscriptions and Mannerist mouldings decorate the rest of the main façade. Notable in the interior is the elaborate tiled ceiling in the legislative chamber.