ISTRIA, a peninsula of Italy, in the territory of Venice, lying in the north part of the Adriatic sea. It is bounded by Carniola on the north; and on the south, east, and west, by the sea. The air is unwholesome, especially near the coast; but the soil produces plenty of wine, oil, and pastures; there are also quarries of fine marble. One part of it belongs to the Venetians, and the other to the house of Austria. Cabo d'Istria is the capital town.