Boulogne

or Boulogne-sur-= Mer, a fortified seaport of France, Department of Pas de Calais, at the mouth of the Liane. It consists of the upper and lower town. The former is surrounded with lofty walls, and has well planted ramparts; the latter, which is the busine part of the town, has straight and well built streets, In the castle, which dates from 1231, Louis Napoleon was imprisoned in 1840.