The mineral wealth of Argentina is very much less than that of most South American countries. In every part of the Continent the difficulty of extracting the ore and bringing it to the coast is considerable, and tends to impair the value of even rich mines; but in Argentina, where the mineral veins are usually not very abundant, the difficulties have seemed almost insuperable, and consequently the capital employed in mining is small. As might have been expected, the Andine and sub-Andine regions almost monopolise the mining interest. The most famous mine is that at Famatina in La Rioja. The fields cover an area of 720 miles, but they are not ancient workings like most of those in Peru and Bolivia. As was said in the earlier chapters, Argentina was fortunate enough to dispel the suspicion of possessing the precious metals, and, as she is the poorest of South American lands in minerals, so she is richest in all else. But unquestionably she would be still richer, and possibly an important manufacturing community, if petroleum or coal could be discovered in great quantities. To return to Famatina, it is said that some Mexican miners passing by in the eighteenth century were struck by the colour of the river and followed it upward to the mountains, where they discovered great treasure. This mine is called the Mexicana, and is situated at an elevation of 16,500 feet, where the men work in the fashion described by Darwin in Chile. Of late the Government has been at pains to improve the communications, but hitherto the ore (gold, silver, and copper) has not been sufficiently rich to yield much profit. In the neighbourhood silver and copper mines have been worked fitfully, and occasionally fortunes have been made; but the unsettled state of the country and the death or disappearance of those who knew the secrets of the hidden ore were unfavourable to enterprise. All over the two continents it is believed that discoveries of fabulous wealth would be made if the Indians told all they knew; but they keep their secrets tenaciously, and make prospecting unsafe.