Roman in origin, the earliest records of historical importance regarding Costacciaro date from the 13th century, when the old castle on the Flaminian Way below Mt. Cucco was purchased by the Commune of Gubbio, to which it remained tied until being annexed to the Papal States (17th century) and later to the Kingdom of Italy (1860). ART, CULTURE, ENVIRONMENT
Among the monuments to be seen in the historic center is the Church of San Francesco (mid-13th century), with a Romanesque façade built using limestone from Mt. Cucco. Inside the church are frescoes in the style of Matteo da Gualdo and, underneath the high altar, the remains of Blessed Tommaso, a Camaldolite monk and the village's patron. Also of interest are the four gates that opened through Costacciaro's circle of walls (Porta dell'Orologio, Porta del Trióne [also known as Porta del Rivellino], Porta di Guerrino Gambucci, and Porta del Monumento [also known as Porta di San Lorenzo]) and the ruins of the fortress and of the walls with the 13th-century Civic Tower. As regards nature and the landscape, Mt. Cucco Park is interesting not only for its meadows and woods, but above all for its cave system (karstic phenomena), beech woods, gorges, high elevation springs and pure streams. The area is a true paradise for hiking, spelunking and hang-gliding enthusiasts. There is a School of Speleology at the Centro Nazionale di Speleologia in Costacciaro, located in the former monastery of the Poor Clares, along with a museum of the karst areas of Mt. Cucco.