Falmouth, a parliamentary borough and seaport of Cornwall, England, beautifully situated on the S. W. side of a harbor on the channel, at the mouth of the river Fal, 45 m. S. W. of Plymouth; pop. in 1871, 5,294. It is on a steep acclivity, reaching to the water's edge, and consists mainly of one long narrow street. It has many good stone houses, and a plentiful supply of water in the N. and S. quarters, where the ground is arranged in terraces. The harbor, one of the finest in Great Britain, is formed by the estuary of the Fal. It is 12 to 18 fathoms deep, and can contain 500 vessels. It is defended on the west by Pen-dennis castle, and on the east by St. Mawes castle, both built by Henry VIII. and improved by Elizabeth. Pendennis castle underwent a long siege by Cromwell, traces of whose encampment near by are still visible. It now contains barracks, storehouses, magazines, etc. Sir Walter Raleigh visited the harbor on his return from the coast of Guiana, and first called attention to its great advantages, which had till then been altogether overlooked. The entrance is about 1 m. wide, and the bay, which runs 6 or 7 m. inland, is a favorite resort of British vessels in time of war.

Before the introduction of mail steamers it was the principal station for the Spanish, Portuguese, and American packet service, and carried on an extensive trade with those countries. It exports pilchards, which are taken off its coast, tin, and copper, and imports timber, hemp, tallow, rum, sugar, grain, wine, and fruits. It has large ship-building yards, roperies, breweries, and a flourishing trade in maritime supplies. The number of vessels registered as belonging to the port is 150. The royal Cornwall polytechnic society, the first institution of the kind established in England, founded in 1833 for the encouragement of the sciences, art, and industry, meets annually at Falmouth.