Prior to the French siege of 1704. the Castle’s defence consisted of an enclosure wall and 4 bastions: The Vineyard Bastion, the Alle Bastion, the Camus Bastion and the Saint Mary Bastion.
The main part of the fortress consisted of the Keep, of the Soldiers’ Barracks and of a well. Below this complex lay the village of Verrua with the Officers’ Quarters, the Royal Square, the Governor’s House, the Church Barracks, the Church of Saint John the Baptist, patron saint of the village, and the Assistance Barracks.
The centre of the fortress square held the bomb-proof depots containing arms and munitions. The only access was through the Assistance Gates which led to the street with the same name connecting the fort with the plains. The only part still visible is the keep with its structures and the Ponte del Soccorso (Assistance Bridge).