The day that we visited Rio Tinto, it was hot, red hot.  We saw a lady sitting under the shade of her RV by the river bank.

Rio Tinto is a river in Southwestern Spain.  It is rich in various minerals (such as copper, silver, gold, iron, etc.) and has been mined since approximately 3,000 BC.  The iron which dissolved in water gives the river its deep reddish hue. And the subsurface rocks on the river bed contain iron and sulfide minerals, which becomes obvious when parts are being exposed above water.

When we made our rounds, it was still hot, red hot.  We asked if she could spare some icy cold water (yeah, you can tell we are from the US).  Her answer began with a disappointing no.  She then said "I have icy cold beers if you want."  She's from Germany. :-)