Mont’Alfonso Fortress is one of the most impressive monuments in the Serchio Valley. It stands just above Castelnuovo Garfagnana, only a few minutes from the town center, and covers an area of about 60,000 square meters, offering beautiful views over the slopes of the Tuscan-Emilian Apennines and the Panie group in the Apuan Alps. It was built between 1579 and 1586 by order of Alfonso II d’Este, based on a design by Marc’Antonio Pasi, to defend Castelnuovo and the Este territory from the Republic of Lucca. The people of Garfagnana also contributed to its construction with the remarkable sum of 30,000 scudi. According to a local legend, the fortress was linked by an underground tunnel to the Rocca Ariostesca, used as a secret passage in case of siege. Today the center of Castelnuovo can be reached on foot along the Ariosto Path, a scenic and romantic walk much loved by visitors.