AOSTA, a duchy of Piedmont, separated by the Alps from Savoy and the Valais, and bounded on the east and south by the Navarese and the provinces of Biella and Yvry. The country is in general mountainous; but there are several valleys of great extent, particularly the Val d'Aosta. By the industry of the inhabitants these low grounds are very fruitful in wine, oil, and pasture; and the mountains abound in iron and copper.