garganta de los infiernos natural reserve, extremadura, spain

pilones garganta infiernos reserve pedestrain bridge track route footpath extremadura spain huge granite roundshaoed forms carved fluvial erosion jerte river marmits tectonic reactivation forest natural pools cold turquoise crystalline water handrail ropes poles upper early autumn season travel sierra tormantos gredos valley hells gorge southwestern side tornacavas cabezuela del valle mountains hills gneiss hydrographic network