Riotinto

Heading north from Palos and Huelva on the N435, you'll reach the turnoff to Minas de Riotinto, the mining town near the source of the Riotinto (literally,"Red River"). The waters are the color of blood because of the minerals leached from the surrounding mountains; this area has some of the richest copper deposits in the world, as well as gold and silver. In 1873 the mines were taken over by the British Rio Tinto Company Ltd., which started to dig an open-pit mine and build a 64-km (40-mi) railway to the port of Huelva to transport mineral ore. The British left in 1954, but mining activity continues today, albeit on a smaller scale.