San Leo, veduta aerea con prospetto della Fortezza

Visitors to the Upper Marecchia Valley can follow an itinerary devoted to the fortresses and castles scattered throughout the area, some very famous examples of which were built by Francesco di Giorgio Martini. He was an architect from Siena who lived at the court of Federico da Montefeltro in Urbino and left signs of his pure Tuscan Renaissance style throughout the region. The splendid Fortezza di San Leo (Fortress of San Leo) stands sturdily on a steep rocky spur jutting up vertically from the valley floor. The fortress, mentioned by Dante in Canto IV of Purgatorio, has a very long history. In 1475 it was thoroughly renovated by Martini, who made it into the cornerstone of the region's defense system, a truly unassailable protective mechanism. The next stop is the Rocca di Maioletto (Fortress of Maioletto), set atop another calcareous cliff that draws attention to the enormous landslide that buried the ancient city of Maiolo. Further to the south, the ruins of the Castelli di Penna e Billi (Castles of Penna and Billi) in the town of Pennabilli are worth a visit, along with the nearby Torre di Bascio (Tower of Bascio), an isolated, square-based structure on the small hill that rises over the village of the same name in the Pennabilli area. The tower, erected in the 12th century, was the watchtower of a castle of which no traces remain today. Still further to the south, the visitor arrives in Casteldelci, known in ancient times as Castrum Ilicis, a very well-preserved village in which the castle of Uguccione della Faggiola stands. Visitors today may admire two towers: the first, called Torre del Monte, is a circular lookout post from the 13th century; the second, the Torre Campanaria, is the tallest of Casteldelci's civic towers, originally built for defensive purposes, but later converted to the role of bell tower of the nearby Chiesa di Santa Maria in Sassetto (Church of St. Mary in Sassetto). Climbing northwards, the visitor comes to Petrella Guidi, an evocative fortified village that is still girded by town walls and preserves an intact urban plan from the 14th century, with very tall old stone houses surrounded by narrow cobblestoned alleys. The tower rises up over the town, set in the midst of a natural landscape, and stands next to the remains of the castle walls. The last stop on the itinerary is a visit to another of Francesco Martini's famous fortresses, the bizarre Rocca Fregoso, which keeps watch over the town center of Sant'Agata Feltria from its perch on the Sasso del Lupo cliff. Martini's hand in the construction of this fairytale-like fortress is most recognizable in the form of the two polygonal bastions that add strength and beauty to the structure.