Capital and chief seaport of Brazil, charmingly situated on the E. coast of Brazil, on the W. shore of a spacious and beautiful bay, 15 m. long, which forms one of the finest natural harbours in the world; stretches some 10 m. along the seaside, and is hemmed in by richly clad hills; streets are narrow and ill kept; possesses a large hospital, public library (180,000 vols.), botanical gardens, arsenal, school of medicine, electric tramways, etc.; has extensive docks, and transacts half the commerce of Brazil; coffee is the chief export; manufactures cotton, jute, silk, tobacco, etc. Great heat prevails in the summer, and yellow fever is common.