Potsdam, chief town of the Prussian province of Brandenburg, and second residence town of the monarch, is situated on an island formed by the lake-like river Havel, a canal, and other waterways, 18 miles by rail SW. of Berlin. It is a handsome city, with broad streets, public gardens, and fine squares. The royal palace (1667-1701), in the park of which are statues of Frederick-William I., Alexander I. of Russia, and Generals Blucher, Gneisenau, Kleist, and Tauenzien; the town-house, a copy of that at Amsterdam; and the military orphanage are the principal public buildings. The Garrison Church, with a steeple 290 feet high, contains the tombs of Frederick-William I. and Frederick II.; and the Friedenskirche the tombs of Frederick-William IV. and the Emperor Frederick III. The Brandenburg Gate is a copy of Trajan's Arch at Rome. Near the town are more than half-a-dozen royal palaces, as Sans-Souci (1747), the favourite residence of Frederick the Great, surrounded by a splendid park and gardens, containing Rauch's monument to Queen Louisa; the palace of Friedrichskron, formerly the New Palace (1763-70); Charlottenhof (1826); the Marble Palace; and Babelsberg. Potsdam has an observatory, and a cadet and other military schools. Its manufactories produce sugar, chemicals, harness, silk, waxcloth, beer, etc. Flower-gardening, especially of violets, is a busy industry. Alexander von Humboldt was a native. Pop. (1880) 48,447; (1905) 61,500.