The country around is perfectly level, a succession of pine-woods and open grounds, and no sign announces the vicinity of the mine, until at length the traveller sees a few huts and some machines for lifting the ore, and then suddenly stands on the brink of an enormous pit, or rather of a vast crater, whose black and precipitous walls inclose an area of at least a mile in circumference. On looking down into the abyss, which descends to a depth of 450 feet, and is here and there enlivened with patches of perennial snow, he perceives along its black walls the still blacker entrances to labyrinthine caves fringed in some parts with long stalactites of ice of aquamarine transparency and colour. From some of these hollows the flames of piles of fir-wood are seen to creep along the hard rock which they are to soften, and the deep gulf is animated by troops of miners, the distant clang of whose hammers, closely resembling the clicking of a number of clocks, forms a strange concert with the creaking noise of the machinery. Attracted by the novelty of the interesting sight, the eye wanders from one object to another, and time steals on rapidly and unperceived—when suddenly a bell tolls, and the scene as suddenly changes. It is noon, and the tuns, which before were hauled up from the deep laden with ore, are now seen ascending with a living freight—men, women, and children—standing quite unconcernedly on the narrow edge of the tub, and holding with one hand the chain to which it is attached. Soon a deathlike silence reigns in the pit—a striking contrast with the noise and life it erewhile displayed—and now loud shouts are heard, warning all those who may have remained behind that the battery prepared during the previous working hours is about to explode. Again a profound silence—and then loud thunder bursts forth, with many an echo, from the depth of the abyss. For several minutes the whole neighbourhood trembles as if shaken by an earthquake. Through the black clouds of smoke which ascend from the gulf, pieces of stone or ore are hurled upwards, frequently far beyond the brink of the pit, and most of the detonations are followed by the crash of the falling fragments rent by the explosion from the mother- rock. For many centuries this remarkable mine has afforded employment to many hundreds of workmen, without showing any signs of exhaustion, for its mighty mass of magnetic iron-ore descends to an unknown depth and seems to be practically inexhaustible. Though the mineral resources of Spain are immense, yet its iron-industry is so little developed that more than two-thirds of the excellent ores of Biscay, instead of being smelted in the country, are exported to France and England.