Dvigrad ("Twin-town"; , Istriot: Docastei), is an abandoned medieval town in central Istria, west Croatia. It is located in the Draga valley. The history of the settlement is prehistoric; it remained inhabited until the 18th century.
The Regional Programme for Cultural and Natural Heritage in South East Europe is attempting to preserve and reconstruct the town.
The castle has also been known as Duo Castra and Dvograd.