SIEBENGEBIRGE (" The Seven Hills ")  , a cluster of hills in Germany, on the Rhine, 6 m. above Bonn . They are of volcanic origin, and form the north-western spurs of the Westerwald . In no part of the Rhine valley is the scenery more attractive; crag and forest, deep dells and gentle vine-clad slopes,- ruined castles and extensive views over the broad Rhine and the plain beyond combine to render the Siebengebirge the most favourite tourist resort on the whole Rhine . The hills are as follows: the steep Drachenfels (1067 ft.), abutting on the Rhine and surmounted by the. ruins of an old castle; immediately behind it, and connected by a narrow ridge, the Wolkenburg (1076 ft.); lying apart, and to the N. of these, the Petersberg (1096 ft.), with a pilgrimage chapel of St Peter; then, to the S. of these three, a chain of four—viz. the Olberg (1522 ft.), the highest of the range; the Lwenburg (1506 ft.); the Lohrberg (1444 ft.), and, farthest away, the Nonnenstromberg (1107 ft.) . At the foot of the Drachenfels, on the north side, lies the little town of Konigswinter, whence a mountain railway ascends to the summit, and a similar railway runs up the Petersberg . The ruins which crown almost every hill are those of strongholds of the archbishops of Cologne and mostly date from the 12th century . See von Dechen, Geognostischer Fiihrer in das Siebengebirge (Bonn, 1861) ; von Stiirtz, Fiihrer durch das Siebengebirge (Bonn, 1893); Laspeyres, Das Siebengebirge am Rhein (Bonn, 1901) .