The Fortezza Firmafede, also known as the Cittadella, is an imposing defensive structure on the edge of the city walls within the historic center of Sarzana.

During the 15th century, the city became an important strategic point when Lorenzo the Magnificent decided to transform the village into a military stronghold of the Florentine lordship. The pre-existing fortification, built by the Pisans in the 13th century, was completely destroyed and rebuilt. In 1496, the fortress passed to the Banco di San Giorgio and from 1562 to the Republic of Genoa, remaining there until 1797. In the 19th century, with the annexation of the Republic to the Kingdom of Sardinia and the radical changes in defensive strategies, the fortress was first used as a police barracks and later as a prison until the 1970s.

Today, the fortress, fully restored, hosts exhibition spaces, festivals, and cultural events. Since 2016, its spaces also house the Museum of Fortresses (MudeF), which through an interactive and multimedia path tells the history and characteristics of Lunigiana through its fortresses, customs, and traditions, placing them in their housing and historical context.