The most westerly and most densely populated of the Prussian provinces, lies within the valleys of the Rhine and the Lower Moselle, and borders on Belgium and the Netherlands; is mountainous and forest-clad, except in the fertile plains of the N. and in the rich river valleys, where vines, cereals, and vegetables are extensively cultivated; large quantities of coal, iron, zinc, and lead are mined; as an industrial and manufacturing province it ranks first in Germany. Coblenz (capital), Aix-la-Chapelle, Bonn, and Cologne are among its chief towns; was formed in 1815 out of several smaller duchies.