CARDONA (perhaps the anc. Udura), a town of north eastern Spain, in the province of Barcelona; about 20m. N.W. of Mauresa, the nearest railway station. Pop. (192o) 4,139. Car dona, built on a hill nearly surrounded by the river Cardoner, is dominated by a castle with triple 13th century walls and a fine Romanesque chapel (founded 1040) . It is celebrated for exten sive rock salt deposits which form a neighbouring hill 26oft. high and 3m. in circumference. The salt, largely translucent, rests on sandstone and is covered by a thick layer of clay. The hill is worked like a mine and the rock is carved in Cardona into images, crucifixes, etc.