city, North Rhine–Westphalia Land (state), northwestern Germany. It lies near the left bank of the Rhine River, south of Cologne. It was a stronghold of the electors of Cologne from 1285 onward, and its Baroque Augustusburg Castle (1725), with extensive gardens and a famous staircase by Balthasar Neumann (Neumann, Balthasar), was their summer residence. Within Augustusburg's gardens is the smaller Falkenlust (1733), a hunting lodge by François de Cuvilliés (Cuvilliés, François de, The Elder). The castles were designated a UNESCO World Heritage site in 1984.

After 1945 Augustusburg Castle was often used by the federal government for official functions. The city is a resort for the people of Cologne; its industries include sugar refining and the manufacture of automobiles. Brown-coal mining was formerly important, but the mines have ceased production. Pop. (2003 est.) 44,115.