Cardona is a town ìn Catalonia, Spain, in the province of Barcelona; about 90 km northwest of the city of Barcelona, on a hill almost surrounded by the river Cardoner, a branch of the Llobregat. Cardona is a picturesque town, with a citadel set high on a hill, and the 14th-century Romanesque Church of St. Vincenç. It is celebrated for the extensive deposit of rock salt in its vicinity. The salt forms a mountain mass (called Muntanya de Sal) covered by a thick bed of a reddish-brown clay, and apparently resting on a yellowish-grey sandstone. It is generally more or less translucent, and large masses of it are quite transparent. The hill has been worked like a mine since Roman times; pieces cut from it have been carved by artists in Cardona into images, crucifixes and many articles of an ornamental kind.