Vignola is dominated by its castle, strategically located where the Panaro leaves the hills for the plain in order to control the ancient via Claudia, which led towards Bologna. This massive building is the sum of a number of different parts which have grown up over time, starting from the X Century. It is dominated by the Donne, Pennello and Nonantola towers, the last the only one built mainly of stones taken from the nearby riverbed and not of brick. The exterior reflects the defensive purpose of the castle, with a large moat, a succession of battlements, doors and the imposts to which chains used to be attached indicating where drawbridges used to be, and the rampart walkway which links the towers. Inside, the castle's residential character is more obvious. Low down, the sala dei Contrari and sala dei Grassoni are now used for conferences and concerts, while the rooms on the ground floor are known as the Lion, Leopard, Dove and Ring (Leoni, Leopardi, Colombe and Anelli) rooms, after the motifs in the frescoes on the walls. The state rooms are on the ground floor, with the Studio and the Chapel, frescoed in late Gothic style by the Maestro di Vignola.