The RÃo Tinto, snaking through southwestern Spain, is unlike any other river on Earth. Its unique red and orange color isn't a product of colorful pebbles or blooming flowers, but rather a result of its extreme chemical makeup. The RÃo Tinto is incredibly acidic, with a pH of around 2, and boasts very high levels of iron and heavy metals. This otherworldly appearance is a … [Read more...] about The Otherworldly RÃo Tinto: A River of Fire