The principal river of Galicia is the Minho, with its tributary the Sil. Each of these rises, though at some distance apart, from the southern side of the Cantabrian mountains, much nearer to the waters of the Bay of Biscay than to those of the Atlantic, into which they flow. They take thence a southerly and south-westerly course, until they unite a few miles above Orense. The lower part of the united course, which bears the name of the Minho, forms from Melgaco to the sea the frontier between the kingdoms of Portugal and Spain. The remaining rivers of Galicia are numerous but of little importance: the Tambre is the largest of those which fall into the Atlantic on the west; while on the north the sources of the Eo and the Navia overlap those of the Minho, and take their rise from the mountains which border on Leon. The whole country is exceedingly well watered. Both in its agricultural character as a grazing country, and in its flora and fauna, it resembles the milder portions of southern Ireland and of Devonshire, but with occasional products of a warmer zone. The rivers of the Asturias, Santander, and of the Basque provinces, all partake of the same general character. In the upper part of their courses they are mere mountain torrents, their course is rapid but short, and they are of but little use for navigation, though occasionally small but insecure harbours are formed at their mouth. The only great exception to this is the Nervion, on which Bilbao is situated, and which is navigable for eight miles from its mouth. The waters of the Bidassoa, the Deva, and others, are, however, utilized for the transport of ore from the mines and ironworks along the course. The Bidassoa, for some ten miles before it enters the Bay of Biscay at Cape Figueras forms the boundary between France and Spain; about four miles from its issue, between Irun and Behobie, is the celebrated Isle des Faisans, where, in 1659, the marriage was arranged between Louis XIV. and the Infanta, which eventually placed the Bourbons on the throne of Spain. The Bidassoa is the last of the northern rivers of Spain which falls into the Atlantic.