a town of France, capital of a cognominal arrondissement in the department of Seine-et-Oise, is pleasantly situated on the left bank of the Seine, and connected with Limay, on the opposite bank, by two bridges and the island of Champion, which divides the river into two streams; 30 miles W.N.W. of Paris. The principal buildings are,—the church of Notre Dame, a Gothic edifice in the pointed style, with two towers and a roof of coloured tiles, which has been recently restored; the tower of St Maclou, also a Gothic structure, and the only remains of a church of the fourteenth century; the court-house; and the town-hall. It has flour-mills, tanneries, and breweries, and some trade in corn, wine, leather, &c. Mantes was taken, and reduced to ashes, by William the Conqueror, in 1087. Pop. (1851) of the town, 4298; of the arrondissement, 58,488.