series of petroglyphs depicting a giraffe, an onyx, footprints, small animals and birds on red sandstone

soil rock geology sand formation carving food series petroglyphs depicting giraffe onyx footprints small animals birds red sandstone unesco twyfelfontein site kunene region namibia series petroglyphs engravings depicting giraffe onyx footprints small animals birds red sandstone unesco twyfelfontein site region namibia rock engraving archaeological hunter-gatherer communities world heritage desert landscape nature stone erosion travel outdoors destinations archaeology beautiful drawing famous culture art archeology antique ancient africa