A 100 km river called Rio Tinto, in Huelva, southern Spain. The color of the river is like wine, hence its name, and this color is derived from minerals such as pyrite or iron + copper sulfide. The bacteria cause oxidation of the minerals and the acidity of the river is caused by sulfuric acid. Photographically it is a paradise for lovers of abstractions and creative photography. Sometimes it looks like an alien world. For four days I went to 40º C and they seemed few to me.