an important mining town in Austrian Illyria, duchy of Carniola, and circle of Adelsberg, in an alpine valley, on a small river of the same name, and 23 miles W.S.W. of Laybach. The quicksilver mines of Idria, and those of Almaden in Spain, are the richest in Europe. They afford employment to 600 or 700 persons, of whom about 500 are miners. They have a regular uniform, and are enrolled in a corps. The annual product of the mines is restricted by government to 150 tons. The descent is by 757 steps cut out of the solid rock, and the greatest depth attained is about 140 fathoms. Formerly the labour of the mines was a punishment decreed on state prisoners, but now the occupation is eagerly coveted. Medical advice and medicines are furnished to the workmen gratis, and when disabled, they are provided for by government. The widows and orphans of miners are entitled to a pension. Pop. about 4000.