Riesengebirge (Giant mountains), a range of mountains partly separating Prussian Silesia from Bohemia, and with the Lusatian range forming a continuation E. of the river Elbe of the Erzgebirge range W. of that river. The Riesengebirge belong to the N. W. division of the Sudetic mountain system, and pursue a S. E. course from the sources of the Bober to those of the southern Neisse until they are merged in the Glatzergebirge, of the Sudetic mountains proper. The range extends about 75 m., with a breadth of 30 m., and is of the same general geological structure with the Erzgebirge, the rocks being chiefly metamor-phic slates and granites, and productive in a similar variety of valuable ores. Those of iron are especially abundant, and some of the earliest establishments for producing that metal were in this region. The highest summits are the Schneekoppe, which rises to an altitude of upward of 5,000 ft., and the Hohes Rad, and the Grosse and Kleine Sturmhaube, all of which are about 4,500 ft. high.