ALTENA, a circle in the government of Arenburg and Prussian province of Westphalia. Its extent is 138 square miles, or 88,320 acres. The chief rivers are the Lenne, which receives the waters of the Nette and the Erse, and the Wipper, both of which run to the Rhine. The agriculture is bad, and in many parts can scarcely produce oats. It has some pasture land, and, besides, yields wood, game, iron, marble, and good stones for building. Its population, which amounts to 27,996, depends almost wholly on the several manufactures which are spread over the whole circle. These comprehend almost every species of iron goods, which, though clumsy in form, are very substantial, and find a ready sale.