ALCANTARA, a small, but very strong city of Estremadura, in Spain. It gives name to one of the three orders of knighthood. It is seated on the banks of the Tajo or Tagus, 21 miles from Coria, in a very fruitful soil, and is celebrated for its bridge over that river. This was built in the time of the emperor Trajan, as appears by an inscription over one of the arches, by the people of Lusitania, who were assessed to supply the expence. It is raised 200 feet above the level of the water; and though it consists but of six arches, is 670 feet in length, and 28 in breadth. At the entrance of the bridge, there is a small antique chapel hewn in a rock by the ancient Pagans, who dedicated it to Trajan, as the Christians did to St Julian. This city was built by the Moors, on account of the convenience of this bridge; which is at a place where the Tajo is very deep, running between two high steep rocks: for this reason they called it Al-Cantara, which in their language signifies the Bridge. It was taken from them in 1214, and given to the knights of Calatrava, who afterwards assumed the name of Alcantara. It was taken by the earl of Galway, in April 1706, and retaken by the French in November following. It is 45 miles from Madrid, and 125 from Seville. W. Long. 7. 12. N. Lat. 39. 30.