"No one c one can look at a map of the Iberian Peninsula without being struck by the curious way in which it is unequally divided between two independent countries. Spain occupies by far the larger part of the Peninsula, leaving to Portugal only a narrow strip on the western seaboard some one hundred miles wide and three hundred and forty long. Besides, the two countries are separated the one from the other by merely artificial boundaries. The two largest rivers of the Peninsula, the Douro and the Tagus, rise in Spain, but finish their course in Portugal, and the Guadiana runs for some eighty miles through Portuguese territor before acting for a second time as a boundar y between the two countries. The same, to a lesser degree, is true of the mountains. The Gerez and the Marão are only offshoots of the Cantabrian mountains, and the Serra da Estrella in Beira is but a continuation of the Sierra de Gata which separates Leon from Spanish Estremadura. Indeed the only natural frontiers are formed by the last thirty miles of the Minho in the north, by about eighty miles of the Douro, which in its deep and narrow gorge really separates Traz os Montes from Leon; by a few miles of the Tagus, and by the Guadiana both before and after it runs through a part of Alemtejo."