The Citadel is a fortress located above the city built during the Habsburg period between 1715 and 1735.
The Citadel aimed to ensure the control over the city and was built according to the plans of the military architect Giovanni Visconti Murando. The fortress was surrounded by a hill and inside included administrative buildings, garrisons, a weapons cache, etc.
The Citadel fortress was surrounded by bastions and provided a stronghold and a tower.
In many situations the fortress was used as a prison, especially during the Revolution of 1848.
At the top of the hill is erected an iron cross, largely in the memory of those imprisioned in the fortress' prison.