PERNAU, a fortified seaport-town of European Russia, in the government of Livonia, stands on a flat sandy heath at the mouth of the Pernau, on the Gulf of Riga, 102 miles N.N.E. of Riga. It is well and regularly built; and contains two Lutheran and one Greek church, several schools, an orphan hospital and various other benevolent institutions. The harbour has a bar at its mouth, which obstructs the entrance of large vessels; but, notwithstanding, there is a considerable trade carried on in corn, flax, hemp, timber, leather, &c. From its low situation, it is exposed to inundation. Many remains of antiquity have been discovered in the neighbourhood of Pernau. Pop. (1849) 5740.