The huge edifice at the intersection of Corso Galileo Ferraris and Via Cernaia is all that remains today of Turin's magnificent historic fortifications. Southwest of the Quadrilateral, a formidable and imposing pentagonal fortress was built by Duke Emmanuel Philibert in the mid-16th century. The Citadel was the last bastion in the epic siege by French and Spanish troops in 1706, during which the soldier Pietro Micca heroically sacrificed his life to foil the enemy's final attempt to conquer Turin and with it the state of Savoy and domination of Europe. Sadly the star-shaped fortress no longer exists, as it was demolished in the mid-19th century.
The Citadel is open to the public and used for temporary exhibitions. Aside from the Cathedral, the keep is the only remaining Renaissance building in Turin. Its proportions are stunning, especially inside, with the large central hall, horse parades, soldiers' steps and the terrace overlooking the gardens.