The historic centre encircles the unfinished Rocca (or ducal palace) whose building plans have been attributed to Antonio da Sangallo the Younger. An archway with a clock tower over it leads to the palace. The parish church of Sant'Ermete features a sixteenth-century baptismal font. The church of San Rocco has several frescoes from the Mannerist school, while the church of Madonna del Giglio has several notable frescoes dating to the fifteenth century, including Our Lady of the Lilies and a Crucifixion by the Umbrian school (sixteenth century). The Civic Museum features exhibits with Etruscan and Renaissance artefacts found in the area around Castro. The funerary furnishings of the Civiltà di Rinaldone and the Etruscan sculptures from the Castro necropolises are also quite interesting.

There are also artefacts from the Roman and Longobard period, as well as six thirteenth-century frescoes from the hermitage of Poggio Conte. A lovely portal attributed to Antonio da Sangallo the Younger is evidence of the destroyed city of Castro.

The ruins of the sixteenth-century city of Castro are a short distance from the town. Planned for the most part by Antonio da Sangallo the Younger, it was the capital of the Duchy of Castro established by Paul III in 1537 for his son Pier Luigi and it was completely destroyed in 1649 by the papal troops of Innocent X. The medieval hermitages of Poggio Conte and Chiusa del Vescovo are evocative sites. These rocky settlements are composed of a church and living quarters. Because of their architectural and pictorial decorations, as well as the attempt to achieve an elaborate and functional subdivision of the living area, they represent one of the most important artistic representations of the history of Castro's civilisation.

The Etruscan necropolis is located near the ruins of Castro: the semi-cubic monumental tomb dating to the sixth century BC is striking and its sculptural decorations can be admired at the Civic Museum. The Biga tomb dates to the same period.