abstract angles backdrop background barrier bolders boulders cemented coated concrete constructed cover covered erosion-prevention fitted hill mortar perspectives random randomly-coursed Rendered retaining-rocks retaining-wall rock rocks rocky rough rugged secure security slope sloping solid stone stone-walled stones stonework strength strong surface surfaces texture textures uneven variations variety wall walled well-built aerial aeroplane airplane appearance arial below bushland central-Australia country-side distance distant expanse flying formations from-above geologically-significant height high isolated landscape lined lines looking-down mountainous movement moving outback panoramic panoramic-views remote riverbeds roads rural scenery scenic shadows sightseeing sparse sunlight sunshine terrain travel travelling undulating valleys vegetation