montes obarenes-san zadornil natural park, spain

desfiladero puron path montes obarenes san zadornil natural park herran merindades burgos castile leon spain europe walk trekk trekking route walking tour mountain ravine canyon valley river eroded riverbed geology rock formation landscape scenery nature wildlife environment ecosystem biosphere tourism ecotourism tranquil scene view conservation area wildland recreation environmental observation conservancy protection travel holidays del rio purã³n obarenes-san herrã¡n castilla leã³n puro³n