Renowned also as fortress of Santa Barbara or Swabian castle, the Emperor`s Castle is a sort of historical anomaly: indeed, it is the sole Swabian architecture in northern Italy.

The castle was built in the 13th century by order of Frederick II Duke of Swabia as part of a project that would allow him to control the major lines of communication between Germany and Italy. Architect Riccardo da Lentini began the construction works in 1248 on a strip of land the Emperor had received from a ghibelline family.

The square building features eight towers, two of which belonged to a pre-existing fortified structure, crowned with swallowtail battlements. At the sides of the entrance are two lions, the symbols of the imperial house.